linq - Page 159 - Developer IT

How does Array.ForEach() compare to standard for loop in C#?

- by DaveN59

I pine for the days when, as a C programmer, I could type: memset( byte_array, '0xFF' ); and get a byte array filled with 'FF' characters. So, I have been looking for a replacement for this: for (int i=0; i < byteArray.Length; i++) { byteArray[i] = 0xFF; } Lately, I have been using some of the new C# features and have been using this approach instead: Array.ForEach<byte>(byteArray, b => b = 0xFF); Granted, the second approach seems cleaner and is easier on the eye, but how does the performance compare to using the first approach? Am I introducing needless overhead by using Linq and generics? Thanks, Dave

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C# Improved algorithm

- by generixs

I have been asked at interview (C# 3.0) to provide a logic to remove a list of items from a list. I responded int[] items={1,2,3,4}; List<int> newList = new List<int>() { 1, 2, 3, 4, 5, 56, 788, 9 }; newList.RemoveAll((int i) => { return items.Contains(i); }); 1) The interviewer replied that the algorithm i had employed will gradually take time if the items grow and asked me to give even better and faster one.What would be the efficient algorithm ? 2) How can i achieve the same using LINQ? 3) He asked me to provide an example for Two-Way-Closure? (General I am aware of closure, what is Two-Way-Closure?, I replied there is no such term exists,but he did not satisfy).

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Creating a dynamic, extensible C# Expando Object

- by Rick Strahl

I love dynamic functionality in a strongly typed language because it offers us the best of both worlds. In C# (or any of the main .NET languages) we now have the dynamic type that provides a host of dynamic features for the static C# language. One place where I've found dynamic to be incredibly useful is in building extensible types or types that expose traditionally non-object data (like dictionaries) in easier to use and more readable syntax. I wrote about a couple of these for accessing old school ADO.NET DataRows and DataReaders more easily for example. These classes are dynamic wrappers that provide easier syntax and auto-type conversions which greatly simplifies code clutter and increases clarity in existing code. ExpandoObject in .NET 4.0 Another great use case for dynamic objects is the ability to create extensible objects - objects that start out with a set of static members and then can add additional properties and even methods dynamically. The .NET 4.0 framework actually includes an ExpandoObject class which provides a very dynamic object that allows you to add properties and methods on the fly and then access them again. For example with ExpandoObject you can do stuff like this:dynamic expand = new ExpandoObject(); expand.Name = "Rick"; expand.HelloWorld = (Func<string, string>) ((string name) => { return "Hello " + name; }); Console.WriteLine(expand.Name); Console.WriteLine(expand.HelloWorld("Dufus")); Internally ExpandoObject uses a Dictionary like structure and interface to store properties and methods and then allows you to add and access properties and methods easily. As cool as ExpandoObject is it has a few shortcomings too: It's a sealed type so you can't use it as a base class It only works off 'properties' in the internal Dictionary - you can't expose existing type data It doesn't serialize to XML or with DataContractSerializer/DataContractJsonSerializer Expando - A truly extensible Object ExpandoObject is nice if you just need a dynamic container for a dictionary like structure. However, if you want to build an extensible object that starts out with a set of strongly typed properties and then allows you to extend it, ExpandoObject does not work because it's a sealed class that can't be inherited. I started thinking about this very scenario for one of my applications I'm building for a customer. In this system we are connecting to various different user stores. Each user store has the same basic requirements for username, password, name etc. But then each store also has a number of extended properties that is available to each application. In the real world scenario the data is loaded from the database in a data reader and the known properties are assigned from the known fields in the database. All unknown fields are then 'added' to the expando object dynamically. In the past I've done this very thing with a separate property - Properties - just like I do for this class. But the property and dictionary syntax is not ideal and tedious to work with. I started thinking about how to represent these extra property structures. One way certainly would be to add a Dictionary, or an ExpandoObject to hold all those extra properties. But wouldn't it be nice if the application could actually extend an existing object that looks something like this as you can with the Expando object:public class User : Westwind.Utilities.Dynamic.Expando { public string Email { get; set; } public string Password { get; set; } public string Name { get; set; } public bool Active { get; set; } public DateTime? ExpiresOn { get; set; } } and then simply start extending the properties of this object dynamically? Using the Expando object I describe later you can now do the following:[TestMethod] public void UserExampleTest() { var user = new User(); // Set strongly typed properties user.Email = "[email protected]"; user.Password = "nonya123"; user.Name = "Rickochet"; user.Active = true; // Now add dynamic properties dynamic duser = user; duser.Entered = DateTime.Now; duser.Accesses = 1; // you can also add dynamic props via indexer user["NickName"] = "AntiSocialX"; duser["WebSite"] = "http://www.west-wind.com/weblog"; // Access strong type through dynamic ref Assert.AreEqual(user.Name,duser.Name); // Access strong type through indexer Assert.AreEqual(user.Password,user["Password"]); // access dyanmically added value through indexer Assert.AreEqual(duser.Entered,user["Entered"]); // access index added value through dynamic Assert.AreEqual(user["NickName"],duser.NickName); // loop through all properties dynamic AND strong type properties (true) foreach (var prop in user.GetProperties(true)) { object val = prop.Value; if (val == null) val = "null"; Console.WriteLine(prop.Key + ": " + val.ToString()); } } As you can see this code somewhat blurs the line between a static and dynamic type. You start with a strongly typed object that has a fixed set of properties. You can then cast the object to dynamic (as I discussed in my last post) and add additional properties to the object. You can also use an indexer to add dynamic properties to the object. To access the strongly typed properties you can use either the strongly typed instance, the indexer or the dynamic cast of the object. Personally I think it's kinda cool to have an easy way to access strongly typed properties by string which can make some data scenarios much easier. To access the 'dynamically added' properties you can use either the indexer on the strongly typed object, or property syntax on the dynamic cast. Using the dynamic type allows all three modes to work on both strongly typed and dynamic properties. Finally you can iterate over all properties, both dynamic and strongly typed if you chose. Lots of flexibility. Note also that by default the Expando object works against the (this) instance meaning it extends the current object. You can also pass in a separate instance to the constructor in which case that object will be used to iterate over to find properties rather than this. Using this approach provides some really interesting functionality when use the dynamic type. To use this we have to add an explicit constructor to the Expando subclass:public class User : Westwind.Utilities.Dynamic.Expando { public string Email { get; set; } public string Password { get; set; } public string Name { get; set; } public bool Active { get; set; } public DateTime? ExpiresOn { get; set; } public User() : base() { } // only required if you want to mix in seperate instance public User(object instance) : base(instance) { } } to allow the instance to be passed. When you do you can now do:[TestMethod] public void ExpandoMixinTest() { // have Expando work on Addresses var user = new User( new Address() ); // cast to dynamicAccessToPropertyTest dynamic duser = user; // Set strongly typed properties duser.Email = "[email protected]"; user.Password = "nonya123"; // Set properties on address object duser.Address = "32 Kaiea"; //duser.Phone = "808-123-2131"; // set dynamic properties duser.NonExistantProperty = "This works too"; // shows default value Address.Phone value Console.WriteLine(duser.Phone); } Using the dynamic cast in this case allows you to access *three* different 'objects': The strong type properties, the dynamically added properties in the dictionary and the properties of the instance passed in! Effectively this gives you a way to simulate multiple inheritance (which is scary - so be very careful with this, but you can do it). How Expando works Behind the scenes Expando is a DynamicObject subclass as I discussed in my last post. By implementing a few of DynamicObject's methods you can basically create a type that can trap 'property missing' and 'method missing' operations. When you access a non-existant property a known method is fired that our code can intercept and provide a value for. Internally Expando uses a custom dictionary implementation to hold the dynamic properties you might add to your expandable object. Let's look at code first. The code for the Expando type is straight forward and given what it provides relatively short. Here it is.using System; using System.Collections.Generic; using System.Linq; using System.Dynamic; using System.Reflection; namespace Westwind.Utilities.Dynamic { /// <summary> /// Class that provides extensible properties and methods. This /// dynamic object stores 'extra' properties in a dictionary or /// checks the actual properties of the instance. /// /// This means you can subclass this expando and retrieve either /// native properties or properties from values in the dictionary. /// /// This type allows you three ways to access its properties: /// /// Directly: any explicitly declared properties are accessible /// Dynamic: dynamic cast allows access to dictionary and native properties/methods /// Dictionary: Any of the extended properties are accessible via IDictionary interface /// </summary> [Serializable] public class Expando : DynamicObject, IDynamicMetaObjectProvider { /// <summary> /// Instance of object passed in /// </summary> object Instance; /// <summary> /// Cached type of the instance /// </summary> Type InstanceType; PropertyInfo[] InstancePropertyInfo { get { if (_InstancePropertyInfo == null && Instance != null) _InstancePropertyInfo = Instance.GetType().GetProperties(BindingFlags.Instance | BindingFlags.Public | BindingFlags.DeclaredOnly); return _InstancePropertyInfo; } } PropertyInfo[] _InstancePropertyInfo; /// <summary> /// String Dictionary that contains the extra dynamic values /// stored on this object/instance /// </summary> /// <remarks>Using PropertyBag to support XML Serialization of the dictionary</remarks> public PropertyBag Properties = new PropertyBag(); //public Dictionary<string,object> Properties = new Dictionary<string, object>(); /// <summary> /// This constructor just works off the internal dictionary and any /// public properties of this object. /// /// Note you can subclass Expando. /// </summary> public Expando() { Initialize(this); } /// <summary> /// Allows passing in an existing instance variable to 'extend'. /// </summary> /// <remarks> /// You can pass in null here if you don't want to /// check native properties and only check the Dictionary! /// </remarks> /// <param name="instance"></param> public Expando(object instance) { Initialize(instance); } protected virtual void Initialize(object instance) { Instance = instance; if (instance != null) InstanceType = instance.GetType(); } /// <summary> /// Try to retrieve a member by name first from instance properties /// followed by the collection entries. /// </summary> /// <param name="binder"></param> /// <param name="result"></param> /// <returns></returns> public override bool TryGetMember(GetMemberBinder binder, out object result) { result = null; // first check the Properties collection for member if (Properties.Keys.Contains(binder.Name)) { result = Properties[binder.Name]; return true; } // Next check for Public properties via Reflection if (Instance != null) { try { return GetProperty(Instance, binder.Name, out result); } catch { } } // failed to retrieve a property result = null; return false; } /// <summary> /// Property setter implementation tries to retrieve value from instance /// first then into this object /// </summary> /// <param name="binder"></param> /// <param name="value"></param> /// <returns></returns> public override bool TrySetMember(SetMemberBinder binder, object value) { // first check to see if there's a native property to set if (Instance != null) { try { bool result = SetProperty(Instance, binder.Name, value); if (result) return true; } catch { } } // no match - set or add to dictionary Properties[binder.Name] = value; return true; } /// <summary> /// Dynamic invocation method. Currently allows only for Reflection based /// operation (no ability to add methods dynamically). /// </summary> /// <param name="binder"></param> /// <param name="args"></param> /// <param name="result"></param> /// <returns></returns> public override bool TryInvokeMember(InvokeMemberBinder binder, object[] args, out object result) { if (Instance != null) { try { // check instance passed in for methods to invoke if (InvokeMethod(Instance, binder.Name, args, out result)) return true; } catch { } } result = null; return false; } /// <summary> /// Reflection Helper method to retrieve a property /// </summary> /// <param name="instance"></param> /// <param name="name"></param> /// <param name="result"></param> /// <returns></returns> protected bool GetProperty(object instance, string name, out object result) { if (instance == null) instance = this; var miArray = InstanceType.GetMember(name, BindingFlags.Public | BindingFlags.GetProperty | BindingFlags.Instance); if (miArray != null && miArray.Length > 0) { var mi = miArray[0]; if (mi.MemberType == MemberTypes.Property) { result = ((PropertyInfo)mi).GetValue(instance,null); return true; } } result = null; return false; } /// <summary> /// Reflection helper method to set a property value /// </summary> /// <param name="instance"></param> /// <param name="name"></param> /// <param name="value"></param> /// <returns></returns> protected bool SetProperty(object instance, string name, object value) { if (instance == null) instance = this; var miArray = InstanceType.GetMember(name, BindingFlags.Public | BindingFlags.SetProperty | BindingFlags.Instance); if (miArray != null && miArray.Length > 0) { var mi = miArray[0]; if (mi.MemberType == MemberTypes.Property) { ((PropertyInfo)mi).SetValue(Instance, value, null); return true; } } return false; } /// <summary> /// Reflection helper method to invoke a method /// </summary> /// <param name="instance"></param> /// <param name="name"></param> /// <param name="args"></param> /// <param name="result"></param> /// <returns></returns> protected bool InvokeMethod(object instance, string name, object[] args, out object result) { if (instance == null) instance = this; // Look at the instanceType var miArray = InstanceType.GetMember(name, BindingFlags.InvokeMethod | BindingFlags.Public | BindingFlags.Instance); if (miArray != null && miArray.Length > 0) { var mi = miArray[0] as MethodInfo; result = mi.Invoke(Instance, args); return true; } result = null; return false; } /// <summary> /// Convenience method that provides a string Indexer /// to the Properties collection AND the strongly typed /// properties of the object by name. /// /// // dynamic /// exp["Address"] = "112 nowhere lane"; /// // strong /// var name = exp["StronglyTypedProperty"] as string; /// </summary> /// <remarks> /// The getter checks the Properties dictionary first /// then looks in PropertyInfo for properties. /// The setter checks the instance properties before /// checking the Properties dictionary. /// </remarks> /// <param name="key"></param> /// /// <returns></returns> public object this[string key] { get { try { // try to get from properties collection first return Properties[key]; } catch (KeyNotFoundException ex) { // try reflection on instanceType object result = null; if (GetProperty(Instance, key, out result)) return result; // nope doesn't exist throw; } } set { if (Properties.ContainsKey(key)) { Properties[key] = value; return; } // check instance for existance of type first var miArray = InstanceType.GetMember(key, BindingFlags.Public | BindingFlags.GetProperty); if (miArray != null && miArray.Length > 0) SetProperty(Instance, key, value); else Properties[key] = value; } } /// <summary> /// Returns and the properties of /// </summary> /// <param name="includeProperties"></param> /// <returns></returns> public IEnumerable<KeyValuePair<string,object>> GetProperties(bool includeInstanceProperties = false) { if (includeInstanceProperties && Instance != null) { foreach (var prop in this.InstancePropertyInfo) yield return new KeyValuePair<string, object>(prop.Name, prop.GetValue(Instance, null)); } foreach (var key in this.Properties.Keys) yield return new KeyValuePair<string, object>(key, this.Properties[key]); } /// <summary> /// Checks whether a property exists in the Property collection /// or as a property on the instance /// </summary> /// <param name="item"></param> /// <returns></returns> public bool Contains(KeyValuePair<string, object> item, bool includeInstanceProperties = false) { bool res = Properties.ContainsKey(item.Key); if (res) return true; if (includeInstanceProperties && Instance != null) { foreach (var prop in this.InstancePropertyInfo) { if (prop.Name == item.Key) return true; } } return false; } } } Although the Expando class supports an indexer, it doesn't actually implement IDictionary or even IEnumerable. It only provides the indexer and Contains() and GetProperties() methods, that work against the Properties dictionary AND the internal instance. The reason for not implementing IDictionary is that a) it doesn't add much value since you can access the Properties dictionary directly and that b) I wanted to keep the interface to class very lean so that it can serve as an entity type if desired. Implementing these IDictionary (or even IEnumerable) causes LINQ extension methods to pop up on the type which obscures the property interface and would only confuse the purpose of the type. IDictionary and IEnumerable are also problematic for XML and JSON Serialization - the XML Serializer doesn't serialize IDictionary<string,object>, nor does the DataContractSerializer. The JavaScriptSerializer does serialize, but it treats the entire object like a dictionary and doesn't serialize the strongly typed properties of the type, only the dictionary values which is also not desirable. Hence the decision to stick with only implementing the indexer to support the user["CustomProperty"] functionality and leaving iteration functions to the publicly exposed Properties dictionary. Note that the Dictionary used here is a custom PropertyBag class I created to allow for serialization to work. One important aspect for my apps is that whatever custom properties get added they have to be accessible to AJAX clients since the particular app I'm working on is a SIngle Page Web app where most of the Web access is through JSON AJAX calls. PropertyBag can serialize to XML and one way serialize to JSON using the JavaScript serializer (not the DCS serializers though). The key components that make Expando work in this code are the Properties Dictionary and the TryGetMember() and TrySetMember() methods. The Properties collection is public so if you choose you can explicitly access the collection to get better performance or to manipulate the members in internal code (like loading up dynamic values form a database). Notice that TryGetMember() and TrySetMember() both work against the dictionary AND the internal instance to retrieve and set properties. This means that user["Name"] works against native properties of the object as does user["Name"] = "RogaDugDog". What's your Use Case? This is still an early prototype but I've plugged it into one of my customer's applications and so far it's working very well. The key features for me were the ability to easily extend the type with values coming from a database and exposing those values in a nice and easy to use manner. I'm also finding that using this type of object for ViewModels works very well to add custom properties to view models. I suspect there will be lots of uses for this - I've been using the extra dictionary approach to extensibility for years - using a dynamic type to make the syntax cleaner is just a bonus here. What can you think of to use this for? Resources Source Code and Tests (GitHub) Also integrated in Westwind.Utilities of the West Wind Web Toolkit West Wind Utilities NuGet© Rick Strahl, West Wind Technologies, 2005-2012Posted in CSharp .NET Dynamic Types Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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NoSQL with RavenDB and ASP.NET MVC - Part 1

- by shiju

A while back, I have blogged NoSQL with MongoDB, NoRM and ASP.NET MVC Part 1 and Part 2 on how to use MongoDB with an ASP.NET MVC application. The NoSQL movement is getting big attention and RavenDB is the latest addition to the NoSQL and document database world. RavenDB is an Open Source (with a commercial option) document database for the .NET/Windows platform developed by Ayende Rahien. Raven stores schema-less JSON documents, allow you to define indexes using Linq queries and focus on low latency and high performance. RavenDB is .NET focused document database which comes with a fully functional .NET client API and supports LINQ. RavenDB comes with two components, a server and a client API. RavenDB is a REST based system, so you can write your own HTTP cleint API. As a .NET developer, RavenDB is becoming my favorite document database. Unlike other document databases, RavenDB is supports transactions using System.Transactions. Also it's supports both embedded and server mode of database. You can access RavenDB site at http://ravendb.netA demo App with ASP.NET MVCLet's create a simple demo app with RavenDB and ASP.NET MVC. To work with RavenDB, do the following steps. Go to http://ravendb.net/download and download the latest build.Unzip the downloaded file.Go to the /Server directory and run the RavenDB.exe. This will start the RavenDB server listening on localhost:8080You can change the port of RavenDB by modifying the "Raven/Port" appSetting value in the RavenDB.exe.config file.When running the RavenDB, it will automatically create a database in the /Data directory. You can change the directory name data by modifying "Raven/DataDirt" appSetting value in the RavenDB.exe.config file.RavenDB provides a browser based admin tool. When the Raven server is running, You can be access the browser based admin tool and view and edit documents and index using your browser admin tool. The web admin tool available at http://localhost:8080The below is the some screen shots of web admin tool Working with ASP.NET MVC To working with RavenDB in our demo ASP.NET MVC application, do the following steps Step 1 - Add reference to Raven Cleint API In our ASP.NET MVC application, Add a reference to the Raven.Client.Lightweight.dll from the Client directory. Step 2 - Create DocumentStoreThe document store would be created once per application. Let's create a DocumentStore on application start-up in the Global.asax.cs. documentStore = new DocumentStore { Url = "http://localhost:8080/" }; documentStore.Initialise(); The above code will create a Raven DB document store and will be listening the server locahost at port 8080 Step 3 - Create DocumentSession on BeginRequest Let's create a DocumentSession on BeginRequest event in the Global.asax.cs. We are using the document session for every unit of work. In our demo app, every HTTP request would be a single Unit of Work (UoW). BeginRequest += (sender, args) => HttpContext.Current.Items[RavenSessionKey] = documentStore.OpenSession(); Step 4 - Destroy the DocumentSession on EndRequest EndRequest += (o, eventArgs) => { var disposable = HttpContext.Current.Items[RavenSessionKey] as IDisposable; if (disposable != null) disposable.Dispose(); }; At the end of HTTP request, we are destroying the DocumentSession object.The below code block shown all the code in the Global.asax.cs private const string RavenSessionKey = "RavenMVC.Session"; private static DocumentStore documentStore; protected void Application_Start() { //Create a DocumentStore in Application_Start //DocumentStore should be created once per application and stored as a singleton. documentStore = new DocumentStore { Url = "http://localhost:8080/" }; documentStore.Initialise(); AreaRegistration.RegisterAllAreas(); RegisterRoutes(RouteTable.Routes); //DI using Unity 2.0 ConfigureUnity(); } public MvcApplication() { //Create a DocumentSession on BeginRequest //create a document session for every unit of work BeginRequest += (sender, args) => HttpContext.Current.Items[RavenSessionKey] = documentStore.OpenSession(); //Destroy the DocumentSession on EndRequest EndRequest += (o, eventArgs) => { var disposable = HttpContext.Current.Items[RavenSessionKey] as IDisposable; if (disposable != null) disposable.Dispose(); }; } //Getting the current DocumentSession public static IDocumentSession CurrentSession { get { return (IDocumentSession)HttpContext.Current.Items[RavenSessionKey]; } } We have setup all necessary code in the Global.asax.cs for working with RavenDB. For our demo app, Let’s write a domain class public class Category { public string Id { get; set; } [Required(ErrorMessage = "Name Required")] [StringLength(25, ErrorMessage = "Must be less than 25 characters")] public string Name { get; set;} public string Description { get; set; } } We have created simple domain entity Category. Let's create repository class for performing CRUD operations against our domain entity Category. public interface ICategoryRepository { Category Load(string id); IEnumerable<Category> GetCategories(); void Save(Category category); void Delete(string id); } public class CategoryRepository : ICategoryRepository { private IDocumentSession session; public CategoryRepository() { session = MvcApplication.CurrentSession; } //Load category based on Id public Category Load(string id) { return session.Load<Category>(id); } //Get all categories public IEnumerable<Category> GetCategories() { var categories= session.LuceneQuery<Category>() .WaitForNonStaleResults() .ToArray(); return categories; } //Insert/Update category public void Save(Category category) { if (string.IsNullOrEmpty(category.Id)) { //insert new record session.Store(category); } else { //edit record var categoryToEdit = Load(category.Id); categoryToEdit.Name = category.Name; categoryToEdit.Description = category.Description; } //save the document session session.SaveChanges(); } //delete a category public void Delete(string id) { var category = Load(id); session.Delete<Category>(category); session.SaveChanges(); } } For every CRUD operations, we are taking the current document session object from HttpContext object. session = MvcApplication.CurrentSession; We are calling the static method CurrentSession from the Global.asax.cs public static IDocumentSession CurrentSession { get { return (IDocumentSession)HttpContext.Current.Items[RavenSessionKey]; } } Retrieve Entities The Load method get the single Category object based on the Id. RavenDB is working based on the REST principles and the Id would be like categories/1. The Id would be created by automatically when a new object is inserted to the document store. The REST uri categories/1 represents a single category object with Id representation of 1. public Category Load(string id) { return session.Load<Category>(id); } The GetCategories method returns all the categories calling the session.LuceneQuery method. RavenDB is using a lucen query syntax for querying. I will explain more details about querying and indexing in my future posts. public IEnumerable<Category> GetCategories() { var categories= session.LuceneQuery<Category>() .WaitForNonStaleResults() .ToArray(); return categories; } Insert/Update entityFor insert/Update a Category entity, we have created Save method in repository class. If the Id property of Category is null, we call Store method of Documentsession for insert a new record. For editing a existing record, we load the Category object and assign the values to the loaded Category object. The session.SaveChanges() will save the changes to document store. //Insert/Update category public void Save(Category category) { if (string.IsNullOrEmpty(category.Id)) { //insert new record session.Store(category); } else { //edit record var categoryToEdit = Load(category.Id); categoryToEdit.Name = category.Name; categoryToEdit.Description = category.Description; } //save the document session session.SaveChanges(); } Delete Entity In the Delete method, we call the document session's delete method and call the SaveChanges method to reflect changes in the document store. public void Delete(string id) { var category = Load(id); session.Delete<Category>(category); session.SaveChanges(); } Let’s create ASP.NET MVC controller and controller actions for handling CRUD operations for the domain class Category public class CategoryController : Controller { private ICategoryRepository categoyRepository; //DI enabled constructor public CategoryController(ICategoryRepository categoyRepository) { this.categoyRepository = categoyRepository; } public ActionResult Index() { var categories = categoyRepository.GetCategories(); if (categories == null) return RedirectToAction("Create"); return View(categories); } [HttpGet] public ActionResult Edit(string id) { var category = categoyRepository.Load(id); return View("Save",category); } // GET: /Category/Create [HttpGet] public ActionResult Create() { var category = new Category(); return View("Save", category); } [HttpPost] public ActionResult Save(Category category) { if (!ModelState.IsValid) { return View("Save", category); } categoyRepository.Save(category); return RedirectToAction("Index"); } [HttpPost] public ActionResult Delete(string id) { categoyRepository.Delete(id); var categories = categoyRepository.GetCategories(); return PartialView("CategoryList", categories); } } RavenDB is an awesome document database and I hope that it will be the winner in .NET space of document database world. The source code of demo application available at http://ravenmvc.codeplex.com/

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How to Specify AssemblyKeyFile Attribute in .NET Assembly and Issues

How to specify strong key file in assembly? Answer: You can specify snk file information using following line [assembly: AssemblyKeyFile(@"c:\Key2.snk")] Where to specify an strong key file (snk file)? Answer: You have two options to specify the AssemblyKeyFile infromation. 1. In class 2. In AssemblyInfo.cs [assembly: AssemblyKeyFile(@"c:\Key2.snk")] 1. In Class you must specify above line before defining namespace of the class and after all the imports or usings Example: See Line 7 in bellow sample class using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Reflection;[assembly: AssemblyKeyFile(@"c:\Key1.snk")]namespace Csharp3Part1{ class Person { public string GetName() { return "Smith"; } }}2. In AssemblyInfo.cs You can aslo specify assembly information in AssemblyInfo.cs Example: See Line 16 in bellow sample AssemblyInfo.csusing System.Reflection;using System.Runtime.CompilerServices;using System.Runtime.InteropServices;// General Information about an assembly is controlled through the following// set of attributes. Change these attribute values to modify the information// associated with an assembly.[assembly: AssemblyTitle("Csharp3Part1")][assembly: AssemblyDescription("")][assembly: AssemblyConfiguration("")][assembly: AssemblyCompany("Deloitte")][assembly: AssemblyProduct("Csharp3Part1")][assembly: AssemblyCopyright("Copyright © Deloitte 2009")][assembly: AssemblyTrademark("")][assembly: AssemblyCulture("")][assembly: AssemblyKeyFile(@"c:\Key1.snk")]// Setting ComVisible to false makes the types in this assembly not visible// to COM components. If you need to access a type in this assembly from// COM, set the ComVisible attribute to true on that type.[assembly: ComVisible(false)]// The following GUID is for the ID of the typelib if this project is exposed to COM[assembly: Guid("4350396f-1a5c-4598-a79f-2e1f219654f3")]// Version information for an assembly consists of the following four values://// Major Version// Minor Version// Build Number// Revision//// You can specify all the values or you can default the Build and Revision Numbers// by using the '*' as shown below:// [assembly: AssemblyVersion("1.0.*")][assembly: AssemblyVersion("1.0.0.0")][assembly: AssemblyFileVersion("1.0.0.0")]Issues:You should not sepcify this in following ways. 1. In multiple classes. 2. In both class and AssemblyInfo.cs If you did wrong in either one of the above ways, Visual Studio or C#/VB.NET compilers shows following Error Duplicate 'AssemblyKeyFile' attribute and warning Use command line option '/keyfile' or appropriate project settings instead of 'AssemblyKeyFile' To avoid this, Please specity your keyfile information only one time either only in one class or in AssemblyInfo.cs file. It is suggested to specify this at AssemblyInfo.cs file You might also encounter the errors like Error: type or namespace name 'AssemblyKeyFileAttribute' and 'AssemblyKeyFile' could not be found. Solution. Please find herespan.fullpost {display:none;} span.fullpost {display:none;}

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Imperative Programming v/s Declarative Programming v/s Functional Programming

- by kaleidoscope

Imperative Programming :: Imperative programming is a programming paradigm that describes computation in terms of statements that change a program state. In much the same way as the imperative mood in natural languages expresses commands to take action, imperative programs define sequences of commands for the computer to perform. The focus is on what steps the computer should take rather than what the computer will do (ex. C, C++, Java). Declarative Programming :: Declarative programming is a programming paradigm that expresses the logic of a computation without describing its control flow. It attempts to minimize or eliminate side effects by describing what the program should accomplish, rather than describing how to go about accomplishing it. The focus is on what the computer should do rather than how it should do it (ex. SQL). A C# example of declarative v/s. imperative programming is LINQ. With imperative programming, you tell the compiler what you want to happen, step by step. For example, let's start with this collection, and choose the odd numbers: List<int> collection = new List<int> { 1, 2, 3, 4, 5 }; With imperative programming, we'd step through this, and decide what we want: List<int> results = new List<int>(); foreach(var num in collection) { if (num % 2 != 0) results.Add(num); } Here’s what we are doing: *Create a result collection *Step through each number in the collection *Check the number, if it's odd, add it to the results With declarative programming, on the other hand, we write the code that describes what you want, but not necessarily how to get it var results = collection.Where( num => num % 2 != 0); Here, we're saying "Give us everything where it's odd", not "Step through the collection. Check this item, if it's odd, add it to a result collection." Functional Programming :: Functional programming is a programming paradigm that treats computation as the evaluation of mathematical functions and avoids state and mutable data. It emphasizes the application of functions.Functional programming has its roots in the lambda calculus. It is a subset of declarative languages that has heavy focus on recursion. Functional programming can be a mind-bender, which is one reason why Lisp, Scheme, and Haskell have never really surpassed C, C++, Java and COBOL in commercial popularity. But there are benefits to the functional way. For one, if you can get the logic correct, functional programming requires orders of magnitude less code than imperative programming. That means fewer points of failure, less code to test, and a more productive (and, many would say, happier) programming life. As systems get bigger, this has become more and more important. To know more : http://stackoverflow.com/questions/602444/what-is-functional-declarative-and-imperative-programming http://msdn.microsoft.com/en-us/library/bb669144.aspx http://en.wikipedia.org/wiki/Imperative_programming Technorati Tags: Ranjit,Imperative Programming,Declarative programming,Functional Programming

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NHibernate 2 Beginner's Guide Review

- by Ricardo Peres

OK, here's the review I promised a while ago. This is a beginner's introduction to NHibernate, so if you have already some experience with NHibernate, you will notice it lacks a lot of concepts and information. It starts with a good description of NHibernate and why would we use it. It goes on describing basic mapping scenarios having primary keys generated with the HiLo or Identity algorithms, without actually explaining why would we choose one over the other. As for mapping, the book talks about XML mappings and provides a simple example of Fluent NHibernate, comparing it to its XML counterpart. When it comes to relations, it covers one-to-many/many-to-one and many-to-many, not one-to-one relations, but only talks briefly about lazy loading, which is, IMO, an important concept. Only Bags are described, not any of the other collection types. The log4net configuration description gets it's own chapter, which I find excessive. The chapter on configuration merely lists the most common properties for configuring NHibernate, both in XML and in code. Querying only talks about loading by ID (using Get, not Load) and using Criteria API, on which a paging example is presented as well as some common filtering options (property equals/like/between to, no examples on conjunction/disjunction, however). There's a chapter fully dedicated to ASP.NET, which explains how we can use NHibernate in web applications. It basically talks about ASP.NET concepts, though. Following it, another chapter explains how we can build our own ASP.NET providers using NHibernate (Membership, Role). The available entity generators for NHibernate are referred and evaluated on a chapter of their own, the list is fine (CodeSmith, nhib-gen, AjGenesis, Visual NHibernate, MyGeneration, NGen, NHModeler, Microsoft T4 (?) and hbm2net), examples are provided whenever possible, however, I have some problems with some of the evaluations: for example, Visual NHibernate scores 5 out of 5 on Visual Studio integration, which simply does not exist! I suspect the author means to say that it can be launched from inside Visual Studio, but then, what can't? Finally, there's a chapter I really don't understand. It seems like a bag where a lot of things are thrown in, like NHibernate Burrow (which actually isn't explained at all), Blog.Net components, CSS template conversion and web.config settings related to the maximum request length for file uploads and ending with XML configuration, with the help of GhostDoc. Like I said, the book is only good for absolute beginners, it does a fair job in explaining the very basics, but lack a lot of not-so-basic concepts. Among other things, it lacks: Inheritance mapping strategies (table per class hierarchy, table per class, table per concrete class) Load versus Get usage Other usefull ISession methods First level cache (Identity Map pattern) Other collection types other that Bag (Set, List, Map, IdBag, etc Fetch options User Types Filters Named queries LINQ examples HQL examples And that's it! I hope you find this review useful. The link to the book site is https://www.packtpub.com/nhibernate-2-x-beginners-guide/book

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Basic Spatial Data with SQL Server and Entity Framework 5.0

- by Rick Strahl

In my most recent project we needed to do a bit of geo-spatial referencing. While spatial features have been in SQL Server for a while using those features inside of .NET applications hasn't been as straight forward as could be, because .NET natively doesn't support spatial types. There are workarounds for this with a few custom project like SharpMap or a hack using the Sql Server specific Geo types found in the Microsoft.SqlTypes assembly that ships with SQL server. While these approaches work for manipulating spatial data from .NET code, they didn't work with database access if you're using Entity Framework. Other ORM vendors have been rolling their own versions of spatial integration. In Entity Framework 5.0 running on .NET 4.5 the Microsoft ORM finally adds support for spatial types as well. In this post I'll describe basic geography features that deal with single location and distance calculations which is probably the most common usage scenario. SQL Server Transact-SQL Syntax for Spatial Data Before we look at how things work with Entity framework, lets take a look at how SQL Server allows you to use spatial data to get an understanding of the underlying semantics. The following SQL examples should work with SQL 2008 and forward. Let's start by creating a test table that includes a Geography field and also a pair of Long/Lat fields that demonstrate how you can work with the geography functions even if you don't have geography/geometry fields in the database. Here's the CREATE command:CREATE TABLE [dbo].[Geo]( [id] [int] IDENTITY(1,1) NOT NULL, [Location] [geography] NULL, [Long] [float] NOT NULL, [Lat] [float] NOT NULL ) Now using plain SQL you can insert data into the table using geography::STGeoFromText SQL CLR function:insert into Geo( Location , long, lat ) values ( geography::STGeomFromText ('POINT(-121.527200 45.712113)', 4326), -121.527200, 45.712113 ) insert into Geo( Location , long, lat ) values ( geography::STGeomFromText ('POINT(-121.517265 45.714240)', 4326), -121.517265, 45.714240 ) insert into Geo( Location , long, lat ) values ( geography::STGeomFromText ('POINT(-121.511536 45.714825)', 4326), -121.511536, 45.714825) The STGeomFromText function accepts a string that points to a geometric item (a point here but can also be a line or path or polygon and many others). You also need to provide an SRID (Spatial Reference System Identifier) which is an integer value that determines the rules for how geography/geometry values are calculated and returned. For mapping/distance functionality you typically want to use 4326 as this is the format used by most mapping software and geo-location libraries like Google and Bing. The spatial data in the Location field is stored in binary format which looks something like this: Once the location data is in the database you can query the data and do simple distance computations very easily. For example to calculate the distance of each of the values in the database to another spatial point is very easy to calculate. Distance calculations compare two points in space using a direct line calculation. For our example I'll compare a new point to all the points in the database. Using the Location field the SQL looks like this:-- create a source point DECLARE @s geography SET @s = geography:: STGeomFromText('POINT(-121.527200 45.712113)' , 4326); --- return the ids select ID, Location as Geo , Location .ToString() as Point , @s.STDistance( Location) as distance from Geo order by distance The code defines a new point which is the base point to compare each of the values to. You can also compare values from the database directly, but typically you'll want to match a location to another location and determine the difference for which you can use the geography::STDistance function. This query produces the following output: The STDistance function returns the straight line distance between the passed in point and the point in the database field. The result for SRID 4326 is always in meters. Notice that the first value passed was the same point so the difference is 0. The other two points are two points here in town in Hood River a little ways away - 808 and 1256 meters respectively. Notice also that you can order the result by the resulting distance, which effectively gives you results that are ordered radially out from closer to further away. This is great for searches of points of interest near a central location (YOU typically!). These geolocation functions are also available to you if you don't use the Geography/Geometry types, but plain float values. It's a little more work, as each point has to be created in the query using the string syntax, but the following code doesn't use a geography field but produces the same result as the previous query.--- using float fields select ID, geography::STGeomFromText ('POINT(' + STR (long, 15,7 ) + ' ' + Str(lat ,15, 7) + ')' , 4326), geography::STGeomFromText ('POINT(' + STR (long, 15,7 ) + ' ' + Str(lat ,15, 7) + ')' , 4326). ToString(), @s.STDistance( geography::STGeomFromText ('POINT(' + STR(long ,15, 7) + ' ' + Str(lat ,15, 7) + ')' , 4326)) as distance from geo order by distance Spatial Data in the Entity Framework Prior to Entity Framework 5.0 on .NET 4.5 consuming of the data above required using stored procedures or raw SQL commands to access the spatial data. In Entity Framework 5 however, Microsoft introduced the new DbGeometry and DbGeography types. These immutable location types provide a bunch of functionality for manipulating spatial points using geometry functions which in turn can be used to do common spatial queries like I described in the SQL syntax above. The DbGeography/DbGeometry types are immutable, meaning that you can't write to them once they've been created. They are a bit odd in that you need to use factory methods in order to instantiate them - they have no constructor() and you can't assign to properties like Latitude and Longitude. Creating a Model with Spatial Data Let's start by creating a simple Entity Framework model that includes a Location property of type DbGeography: public class GeoLocationContext : DbContext { public DbSet<GeoLocation> Locations { get; set; } } public class GeoLocation { public int Id { get; set; } public DbGeography Location { get; set; } public string Address { get; set; } } That's all there's to it. When you run this now against SQL Server, you get a Geography field for the Location property, which looks the same as the Location field in the SQL examples earlier. Adding Spatial Data to the Database Next let's add some data to the table that includes some latitude and longitude data. An easy way to find lat/long locations is to use Google Maps to pinpoint your location, then right click and click on What's Here. Click on the green marker to get the GPS coordinates. To add the actual geolocation data create an instance of the GeoLocation type and use the DbGeography.PointFromText() factory method to create a new point to assign to the Location property:[TestMethod] public void AddLocationsToDataBase() { var context = new GeoLocationContext(); // remove all context.Locations.ToList().ForEach( loc => context.Locations.Remove(loc)); context.SaveChanges(); var location = new GeoLocation() { // Create a point using native DbGeography Factory method Location = DbGeography.PointFromText( string.Format("POINT({0} {1})", -121.527200,45.712113) ,4326), Address = "301 15th Street, Hood River" }; context.Locations.Add(location); location = new GeoLocation() { Location = CreatePoint(45.714240, -121.517265), Address = "The Hatchery, Bingen" }; context.Locations.Add(location); location = new GeoLocation() { // Create a point using a helper function (lat/long) Location = CreatePoint(45.708457, -121.514432), Address = "Kaze Sushi, Hood River" }; context.Locations.Add(location); location = new GeoLocation() { Location = CreatePoint(45.722780, -120.209227), Address = "Arlington, OR" }; context.Locations.Add(location); context.SaveChanges(); } As promised, a DbGeography object has to be created with one of the static factory methods provided on the type as the Location.Longitude and Location.Latitude properties are read only. Here I'm using PointFromText() which uses a "Well Known Text" format to specify spatial data. In the first example I'm specifying to create a Point from a longitude and latitude value, using an SRID of 4326 (just like earlier in the SQL examples). You'll probably want to create a helper method to make the creation of Points easier to avoid that string format and instead just pass in a couple of double values. Here's my helper called CreatePoint that's used for all but the first point creation in the sample above:public static DbGeography CreatePoint(double latitude, double longitude) { var text = string.Format(CultureInfo.InvariantCulture.NumberFormat, "POINT({0} {1})", longitude, latitude); // 4326 is most common coordinate system used by GPS/Maps return DbGeography.PointFromText(text, 4326); } Using the helper the syntax becomes a bit cleaner, requiring only a latitude and longitude respectively. Note that my method intentionally swaps the parameters around because Latitude and Longitude is the common format I've seen with mapping libraries (especially Google Mapping/Geolocation APIs with their LatLng type). When the context is changed the data is written into the database using the SQL Geography type which looks the same as in the earlier SQL examples shown. Querying Once you have some location data in the database it's now super easy to query the data and find out the distance between locations. A common query is to ask for a number of locations that are near a fixed point - typically your current location and order it by distance. Using LINQ to Entities a query like this is easy to construct:[TestMethod] public void QueryLocationsTest() { var sourcePoint = CreatePoint(45.712113, -121.527200); var context = new GeoLocationContext(); // find any locations within 5 kilometers ordered by distance var matches = context.Locations .Where(loc => loc.Location.Distance(sourcePoint) < 5000) .OrderBy( loc=> loc.Location.Distance(sourcePoint) ) .Select( loc=> new { Address = loc.Address, Distance = loc.Location.Distance(sourcePoint) }); Assert.IsTrue(matches.Count() > 0); foreach (var location in matches) { Console.WriteLine("{0} ({1:n0} meters)", location.Address, location.Distance); } } This example produces: 301 15th Street, Hood River (0 meters)The Hatchery, Bingen (809 meters)Kaze Sushi, Hood River (1,074 meters) The first point in the database is the same as my source point I'm comparing against so the distance is 0. The other two are within the 5 mile radius, while the Arlington location which is 65 miles or so out is not returned. The result is ordered by distance from closest to furthest away. In the code, I first create a source point that is the basis for comparison. The LINQ query then selects all locations that are within 5km of the source point using the Location.Distance() function, which takes a source point as a parameter. You can either use a pre-defined value as I'm doing here, or compare against another database DbGeography property (say when you have to points in the same database for things like routes). What's nice about this query syntax is that it's very clean and easy to read and understand. You can calculate the distance and also easily order by the distance to provide a result that shows locations from closest to furthest away which is a common scenario for any application that places a user in the context of several locations. It's now super easy to accomplish this. Meters vs. Miles As with the SQL Server functions, the Distance() method returns data in meters, so if you need to work with miles or feet you need to do some conversion. Here are a couple of helpers that might be useful (can be found in GeoUtils.cs of the sample project):/// <summary> /// Convert meters to miles /// </summary> /// <param name="meters"></param> /// <returns></returns> public static double MetersToMiles(double? meters) { if (meters == null) return 0F; return meters.Value * 0.000621371192; } /// <summary> /// Convert miles to meters /// </summary> /// <param name="miles"></param> /// <returns></returns> public static double MilesToMeters(double? miles) { if (miles == null) return 0; return miles.Value * 1609.344; } Using these two helpers you can query on miles like this:[TestMethod] public void QueryLocationsMilesTest() { var sourcePoint = CreatePoint(45.712113, -121.527200); var context = new GeoLocationContext(); // find any locations within 5 miles ordered by distance var fiveMiles = GeoUtils.MilesToMeters(5); var matches = context.Locations .Where(loc => loc.Location.Distance(sourcePoint) <= fiveMiles) .OrderBy(loc => loc.Location.Distance(sourcePoint)) .Select(loc => new { Address = loc.Address, Distance = loc.Location.Distance(sourcePoint) }); Assert.IsTrue(matches.Count() > 0); foreach (var location in matches) { Console.WriteLine("{0} ({1:n1} miles)", location.Address, GeoUtils.MetersToMiles(location.Distance)); } } which produces: 301 15th Street, Hood River (0.0 miles)The Hatchery, Bingen (0.5 miles)Kaze Sushi, Hood River (0.7 miles) Nice 'n simple. .NET 4.5 Only Note that DbGeography and DbGeometry are exclusive to Entity Framework 5.0 (not 4.4 which ships in the same NuGet package or installer) and requires .NET 4.5. That's because the new DbGeometry and DbGeography (and related) types are defined in the 4.5 version of System.Data.Entity which is a CLR assembly and is only updated by major versions of .NET. Why this decision was made to add these types to System.Data.Entity rather than to the frequently updated EntityFramework assembly that would have possibly made this work in .NET 4.0 is beyond me, especially given that there are no native .NET framework spatial types to begin with. I find it also odd that there is no native CLR spatial type. The DbGeography and DbGeometry types are specific to Entity Framework and live on those assemblies. They will also work for general purpose, non-database spatial data manipulation, but then you are forced into having a dependency on System.Data.Entity, which seems a bit silly. There's also a System.Spatial assembly that's apparently part of WCF Data Services which in turn don't work with Entity framework. Another example of multiple teams at Microsoft not communicating and implementing the same functionality (differently) in several different places. Perplexed as a I may be, for EF specific code the Entity framework specific types are easy to use and work well. Working with pre-.NET 4.5 Entity Framework and Spatial Data If you can't go to .NET 4.5 just yet you can also still use spatial features in Entity Framework, but it's a lot more work as you can't use the DbContext directly to manipulate the location data. You can still run raw SQL statements to write data into the database and retrieve results using the same TSQL syntax I showed earlier using Context.Database.ExecuteSqlCommand(). Here's code that you can use to add location data into the database:[TestMethod] public void RawSqlEfAddTest() { string sqlFormat = @"insert into GeoLocations( Location, Address) values ( geography::STGeomFromText('POINT({0} {1})', 4326),@p0 )"; var sql = string.Format(sqlFormat,-121.527200, 45.712113); Console.WriteLine(sql); var context = new GeoLocationContext(); Assert.IsTrue(context.Database.ExecuteSqlCommand(sql,"301 N. 15th Street") > 0); } Here I'm using the STGeomFromText() function to add the location data. Note that I'm using string.Format here, which usually would be a bad practice but is required here. I was unable to use ExecuteSqlCommand() and its named parameter syntax as the longitude and latitude parameters are embedded into a string. Rest assured it's required as the following does not work:string sqlFormat = @"insert into GeoLocations( Location, Address) values ( geography::STGeomFromText('POINT(@p0 @p1)', 4326),@p2 )";context.Database.ExecuteSqlCommand(sql, -121.527200, 45.712113, "301 N. 15th Street") Explicitly assigning the point value with string.format works however. There are a number of ways to query location data. You can't get the location data directly, but you can retrieve the point string (which can then be parsed to get Latitude and Longitude) and you can return calculated values like distance. Here's an example of how to retrieve some geo data into a resultset using EF's and SqlQuery method:[TestMethod] public void RawSqlEfQueryTest() { var sqlFormat = @" DECLARE @s geography SET @s = geography:: STGeomFromText('POINT({0} {1})' , 4326); SELECT Address, Location.ToString() as GeoString, @s.STDistance( Location) as Distance FROM GeoLocations ORDER BY Distance"; var sql = string.Format(sqlFormat, -121.527200, 45.712113); var context = new GeoLocationContext(); var locations = context.Database.SqlQuery<ResultData>(sql); Assert.IsTrue(locations.Count() > 0); foreach (var location in locations) { Console.WriteLine(location.Address + " " + location.GeoString + " " + location.Distance); } } public class ResultData { public string GeoString { get; set; } public double Distance { get; set; } public string Address { get; set; } } Hopefully you don't have to resort to this approach as it's fairly limited. Using the new DbGeography/DbGeometry types makes this sort of thing so much easier. When I had to use code like this before I typically ended up retrieving data pks only and then running another query with just the PKs to retrieve the actual underlying DbContext entities. This was very inefficient and tedious but it did work. Summary For the current project I'm working on we actually made the switch to .NET 4.5 purely for the spatial features in EF 5.0. This app heavily relies on spatial queries and it was worth taking a chance with pre-release code to get this ease of integration as opposed to manually falling back to stored procedures or raw SQL string queries to return spatial specific queries. Using native Entity Framework code makes life a lot easier than the alternatives. It might be a late addition to Entity Framework, but it sure makes location calculations and storage easy. Where do you want to go today? ;-) Resources Download Sample Project© Rick Strahl, West Wind Technologies, 2005-2012Posted in ADO.NET Sql Server .NET Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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using Generics in C# [closed]

- by Uphaar Goyal

I have started looking into using generics in C#. As an example what i have done is that I have an abstract class which implements generic methods. these generic methods take a sql query, a connection string and the Type T as parameters and then construct the data set, populate the object and return it back. This way each business object does not need to have a method to populate it with data or construct its data set. All we need to do is pass the type, the sql query and the connection string and these methods do the rest.I am providing the code sample here. I am just looking to discuss with people who might have a better solution to what i have done. using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Data; using System.Data.SqlClient; using MWTWorkUnitMgmtLib.Business; using System.Collections.ObjectModel; using System.Reflection; namespace MWTWorkUnitMgmtLib.TableGateway { public abstract class TableGateway { public TableGateway() { } protected abstract string GetConnection(); protected abstract string GetTableName(); public DataSet GetDataSetFromSql(string connectionString, string sql) { DataSet ds = null; using (SqlConnection connection = new SqlConnection(connectionString)) using (SqlCommand command = connection.CreateCommand()) { command.CommandText = sql; connection.Open(); using (ds = new DataSet()) using (SqlDataAdapter adapter = new SqlDataAdapter(command)) { adapter.Fill(ds); } } return ds; } public static bool ContainsColumnName(DataRow dr, string columnName) { return dr.Table.Columns.Contains(columnName); } public DataTable GetDataTable(string connString, string sql) { DataSet ds = GetDataSetFromSql(connString, sql); DataTable dt = null; if (ds != null) { if (ds.Tables.Count 0) { dt = ds.Tables[0]; } } return dt; } public T Construct(DataRow dr, T t) where T : class, new() { Type t1 = t.GetType(); PropertyInfo[] properties = t1.GetProperties(); foreach (PropertyInfo property in properties) { if (ContainsColumnName(dr, property.Name) && (dr[property.Name] != null)) property.SetValue(t, dr[property.Name], null); } return t; } public T GetByID(string connString, string sql, T t) where T : class, new() { DataTable dt = GetDataTable(connString, sql); DataRow dr = dt.Rows[0]; return Construct(dr, t); } public List GetAll(string connString, string sql, T t) where T : class, new() { List collection = new List(); DataTable dt = GetDataTable(connString, sql); foreach (DataRow dr in dt.Rows) collection.Add(Construct(dr, t)); return collection; } } }

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Welcome to my geeks blog

- by bconlon

Hi and welcome! I'm Bazza and this is my geeks blog. I have 20 years Visual Studio mainly C++, MFC, ATL and now, thankfully, C# and I am embarking on the new world (well new to me) of WPF, so I thought I would try and capture my successful...and not so successful...WPF experiences with the geek world. So where to start? WPF? What I know so far... From wiki..."Windows Presentation Foundation (or WPF) is a graphical subsystem for rendering user interfaces in Windows-based applications." Hmm, great but didn't MFC, ATL (my head hurt with that one), and .Net all have APIs to allow me to code against the Windows Graphical Device Interface (GDI)? "Rather than relying on the older GDI subsystem, WPF utilizes DirectX. WPF attempts to provide a consistent programming model for building applications and provides a separation between the user interface and the business logic." OK, different drawing code, same Windows and weren't we always taught to separate our UI, Business Layer and Data Access Layer? "WPF employs XAML, a derivative of XML, to define and link various UI elements. WPF applications can be deployed as standalone desktop programs, or hosted as an embedded object in a website." Cool, now we're getting somewhere. So when they say separation they really mean separation. The crux of this appears to be that you can have creative people writing the UI and making it attractive and intuitive to use, whist the geeks concentrate on writing the Business and Data Access stuff. XAML (eXtensible Application Markup Language) maps XML elements and attributes directly to Common Language Runtime (CLR) object instances, properties and events. True separation of the View and Model. WPF also provides logical separation of a control from its appearance. In a traditional Windows system, all Controls have a base class containing a Windows handle and each Control knows how to render itself. In WPF, the controls are more like those in a Web Browser using Cascading Style Sheet, they are not wrappers for standard Windows Controls. Instead, they have a default 'template' that defines a visual theme which can easily be replaced by a custom template. But it gets better. WPF concentrates heavily on Data Binding where the client can bind directly to data on the server. I think this concept was first introduced in 'Classic' Visual Basic, where you could bind a list directly to a data from an Access database, and you could do similar in ASP .Net. However, the WPF implementation is far superior than it's predecessors. There are also other technologies that I want to look at like LINQ and the Entity Framework, but that's all for now. #

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Speaking at SPTechCon SF 2011 and SPSNOLA 2011

- by Brian Jackett

From Feb 7th-9th I’ll be presenting two sessions at SPTechCon San Francisco 2011. My first presentation is a new session called “The Expanding Developer Toolbox for SharePoint 2010” which covers many of the new tools and functionality available to SharePoint 2010 developers. My second sessions is called “Real World Deployment of SharePoint 2007 Solutions” (presented at last SPTech Con Boston) which covers tips, tricks, and advice on deploying SharePoint 2007 solutions. If you hurry you may still be able to register for this SPTechCon. Click here for registration information. Hope to see you there. In addition to SPTechCon, I’ll also be speaking at SharePoint Saturday New Orleans 2011 on Feb 26th. My presentation is called “Managing SharePoint 2010 Farms with PowerShell”. I’ve given this presentation at a number of recent conferences and it has been popular. I’m excited for this weekend as well since it will be my first time visiting New Orleans. Click here for registration information. Sessions Where: SPTech Con San Francisco 2011 Title: The Expanding Developer Toolbox for SharePoint 2010 Audience and Level: Developer, Beginner/Intermediate Abstract: LINQ to SharePoint, native Visual Studio 2010 support, easier access to logging, Business Connectivity Services… The list of new features and tools available to developers rapidly grew between SharePoint 2007 and 2010. In this session we will cover these and many of the other newest features added for SharePoint developers to utilize. This session is targeted to SharePoint 2007 developers upgrading their skills to SharePoint 2010 or developers new to SharePoint 2010. Where: SPTech Con San Francisco 2011 Title: Real World Deployment of SharePoint 2007 Solutions Audience and Level: Admin/Developer, Intermediate Abstract: “All I have to do is run some STSADM commands to deploy my SharePoint solutions, right?” If you are saying that to yourself then you are missing out on some of the more advanced processes you can employ to deploy and maintain your SharePoint solutions and farm. In this session we will cover lessons learned from 3 years of deploying and automating SharePoint solutions. This will include using a combination of STSADM, PowerShell, SharePoint API and a number of other tools in a real world situation to deploy an entire suite of custom SharePoint solutions. This session is targeted to farm administrators and developers. Prior experience with SharePoint solutions, STSADM and minimal PowerShell experience is suggested. Where: SharePoint Saturday New Orleans Title: Managing SharePoint 2010 Farms with PowerShell Audience and Level: Admin, Beginner Abstract: Having you been using STSADM (or worse hand editing processes) to manage your SharePoint 2007 farms? Are you hearing about needing to learn PowerShell to manage SharePoint 2010 farms? This session will serve as part introduction to PowerShell and part overview of how you can use PowerShell to more efficiently and effectively manage your SharePoint 2010 farm. This session is targeted to farm administrators and IT pros and no previous experience with PowerShell is required. -Frog Out

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Using a WCF Message Inspector to extend AppFabric Monitoring

- by Shawn Cicoria

I read through Ron Jacobs post on Monitoring WCF Data Services with AppFabric http://blogs.msdn.com/b/endpoint/archive/2010/06/09/tracking-wcf-data-services-with-windows-server-appfabric.aspx What is immediately striking are 2 things – it’s so easy to get monitoring data into a viewer (AppFabric Dashboard) w/ very little work. And the 2nd thing is, why can’t this be a WCF message inspector on the dispatch side. So, I took the base class WCFUserEventProvider that’s located in the WCF/WF samples [1] in the following path, \WF_WCF_Samples\WCF\Basic\Management\AnalyticTraceExtensibility\CS\WCFAnalyticTracingExtensibility\ and then created a few classes that project the injection as a IEndPointBehavior There are just 3 classes to drive injection of the inspector at runtime via config: IDispatchMessageInspector implementation BehaviorExtensionElement implementation IEndpointBehavior implementation The full source code is below with a link to the solution file here: [Solution File] using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.ServiceModel.Dispatcher; using System.ServiceModel.Channels; using System.ServiceModel; using System.ServiceModel.Configuration; using System.ServiceModel.Description; using Microsoft.Samples.WCFAnalyticTracingExtensibility; namespace Fabrikam.Services { public class AppFabricE2EInspector : IDispatchMessageInspector { static WCFUserEventProvider evntProvider = null; static AppFabricE2EInspector() { evntProvider = new WCFUserEventProvider(); } public object AfterReceiveRequest( ref Message request, IClientChannel channel, InstanceContext instanceContext) { OperationContext ctx = OperationContext.Current; var opName = ctx.IncomingMessageHeaders.Action; evntProvider.WriteInformationEvent("start", string.Format("operation: {0} at address {1}", opName, ctx.EndpointDispatcher.EndpointAddress)); return null; } public void BeforeSendReply(ref System.ServiceModel.Channels.Message reply, object correlationState) { OperationContext ctx = OperationContext.Current; var opName = ctx.IncomingMessageHeaders.Action; evntProvider.WriteInformationEvent("end", string.Format("operation: {0} at address {1}", opName, ctx.EndpointDispatcher.EndpointAddress)); } } public class AppFabricE2EBehaviorElement : BehaviorExtensionElement { #region BehaviorExtensionElement /// <summary> /// Gets the type of behavior. /// </summary> /// <value></value> /// <returns>The type that implements the end point behavior<see cref="T:System.Type"/>.</returns> public override Type BehaviorType { get { return typeof(AppFabricE2EEndpointBehavior); } } /// <summary> /// Creates a behavior extension based on the current configuration settings. /// </summary> /// <returns>The behavior extension.</returns> protected override object CreateBehavior() { return new AppFabricE2EEndpointBehavior(); } #endregion BehaviorExtensionElement } public class AppFabricE2EEndpointBehavior : IEndpointBehavior //, IServiceBehavior { #region IEndpointBehavior public void AddBindingParameters(ServiceEndpoint endpoint, BindingParameterCollection bindingParameters) {} public void ApplyClientBehavior(ServiceEndpoint endpoint, ClientRuntime clientRuntime) { throw new NotImplementedException(); } public void ApplyDispatchBehavior(ServiceEndpoint endpoint, EndpointDispatcher endpointDispatcher) { endpointDispatcher.DispatchRuntime.MessageInspectors.Add(new AppFabricE2EInspector()); } public void Validate(ServiceEndpoint endpoint) { ; } #endregion IEndpointBehavior } } [1] http://www.microsoft.com/downloads/details.aspx?FamilyID=35ec8682-d5fd-4bc3-a51a-d8ad115a8792&displaylang=en

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Silverlight Cream for November 20, 2011 - 2 -- #1170

- by Dave Campbell

In this Issue: Michael Washington, Oliver Fuh, Jeremy Likness, Derik Whittaker, Jesse Liberty, Jeff Blankenburg(-2-), and Michael Crump. Above the Fold: Silverlight: "Handling Extremely Large Data Sets in Silverlight" Jeremy Likness WP7: "31 Days of Mango | Day #8: Contacts API" Jeff Blankenburg LightSwitch: "LightSwitch Chat Application Using A Data Source Extension" Michael Washington Shoutouts: Michael Palermo's latest Desert Mountain Developers is up Michael Washington's latest Visual Studio #LightSwitch Daily is up Check out Shawn Wildermuth's take on the AppStore and WP7 in general: 40,000 Apps - What Does It Mean? Be sure to check out Jesse Liberty & Paul Betts new book: Programming Reactive Extensions and LINQ, I've just had a little time to look at mine, but don't let the size fool you... this is the good stuff! From SilverlightCream.com: LightSwitch Chat Application Using A Data Source Extension In his latest LightSwitch post, Michael Washington gives up code that will enable two people using the same LightSwitch app to chat. Great detailed tutorial as usual! Handling AdControl Fetching Exception WindowsPhoneGeek turns the blog reigns over to Oliver Fuh for this post about using the AdControl in your WP7 app and handling a common exception you get with the Microsoft AdControl Handling Extremely Large Data Sets in Silverlight In this excerpt from his book, Jeremy Likness discusses reading *LARGE* data sets with Silverlight using 3 different patterns: OData, WCF RIA Services, and MVVM. Using MVVM with the AutoCompleteTextBox in Silverlight 4 Derik Whittaker takes a break from WinRT to discuss the Silverlight 4 AutoCompleteTextBox and MVVM ... including a custom Behavior to allow the backing property to be updated and a command to trigger background searches Yet Another Podcast #52–Peter Torr on Windows Phone Multitasking Jesse Liberty scored Peter Torr on his Latest Yet Another Podcast .. talking about Multitasking on Windows Phone including background agents, the backstack, and other Mango features 31 Days of Mango | Day #8: Contacts API Jeff Blankenburg's Day 8 is about a new namespace on WP7: Microsoft.Phone.UserData ... now giving us the ability to treat the user's contact list like a local database 31 Days of Mango | Day #9: Calendar API On Day 9 in his series, Jeff Blankenburg revisits the Microsoft.Phone.UserData namespace and looks at another set of data: the calendar Want to Decompile Silverlight XAP files? Try JustDecompile Beta! Michael Crump has a post up about the new free developer productivity tool from Telerik that provides assembly browsing and decompiling: JustDecompile ... Just download it! Stay in the 'Light! Twitter SilverlightNews | Twitter WynApse | WynApse.com | Tagged Posts | SilverlightCream Join me @ SilverlightCream | Phoenix Silverlight User Group Technorati Tags: Silverlight Silverlight 3 Silverlight 4 Windows Phone MIX10

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Chunking a List - .NET vs Python

- by Abhijeet Patel

Chunking a List As I mentioned last time, I'm knee deep in python these days. I come from a statically typed background so it's definitely a mental adjustment. List comprehensions is BIG in Python and having worked with a few of them I can see why. Let's say we need to chunk a list into sublists of a specified size. Here is how we'd do it in C# static class Extensions { public static IEnumerable<List<T>> Chunk<T>(this List<T> l, int chunkSize) { if (chunkSize <0) { throw new ArgumentException("chunkSize cannot be negative", "chunkSize"); } for (int i = 0; i < l.Count; i += chunkSize) { yield return new List<T>(l.Skip(i).Take(chunkSize)); } } } static void Main(string[] args) { var l = new List<string> { "a", "b", "c", "d", "e", "f","g" }; foreach (var list in l.Chunk(7)) { string str = list.Aggregate((s1, s2) => s1 + "," + s2); Console.WriteLine(str); } } A little wordy but still pretty concise thanks to LINQ.We skip the iteration number plus chunkSize elements and yield out a new List of chunkSize elements on each iteration. The python implementation is a bit more terse. def chunkIterable(iter, chunkSize): '''Chunks an iterable object into a list of the specified chunkSize ''' assert hasattr(iter, "__iter__"), "iter is not an iterable" for i in xrange(0, len(iter), chunkSize): yield iter[i:i + chunkSize] if __name__ == '__main__': l = ['a', 'b', 'c', 'd', 'e', 'f'] generator = chunkIterable(l,2) try: while(1): print generator.next() except StopIteration: pass xrange generates elements in the specified range taking in a seed and returning a generator. which can be used in a for loop(much like using a C# iterator in a foreach loop) Since chunkIterable has a yield statement, it turns this method into a generator as well. iter[i:i + chunkSize] essentially slices the list based on the current iteration index and chunksize and creates a new list that we yield out to the caller one at a time. A generator much like an iterator is a state machine and each subsequent call to it remembers the state at which the last call left off and resumes execution from that point. The caveat to keep in mind is that since variables are not explicitly typed we need to ensure that the object passed in is iterable using hasattr(iter, "__iter__").This way we can perform chunking on any object which is an "iterable", very similar to accepting an IEnumerable in the .NET land

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Java Space on Parleys

- by Yolande Poirier

Now available! A great selection of JavaOne 2010 and JVM Language Summit 2010 sessions as well as Oracle Technology Network TechCasts on the new Java Space on Parleys website. Oracle partnered with Stephan Janssen, founder of Parleys to make this happen. Parleys website offers a user friendly experience to view online content. You can download some of the talks to your desktop or watch them on the go on mobile devices. The current selection is a well of expertise from top Java luminaries and Oracle experts. JavaOne 2010 sessions: · Best practices for signing code by Sean Mullan · Building software using rich client platforms by Rickard Thulin · Developing beyond the component libraries by Ryan Cuprak · Java API for keyhole markup language by Florian Bachmann · Avoiding common user experience anti-patterns by Burk Hufnagel · Accelerating Java workloads via GPUs by Gary Frost JVM Languages Summit 2010 sessions: · Mixed language project compilation in Eclipse by Andy Clement · Gathering the threads by John Rose · LINQ: language features for concurrency by Neal Gafter · Improvements in OpenJDK useful for JVM languages by Eric Caspole · Symmetric Multilanguage - VM Architecture by Oleg Pliss Special interviews with Oracle experts on product innovations: · Ludovic Champenois, Java EE architect on Glassfish 3.1 and Java EE. · John Jullion-Ceccarelli and Martin Ryzl on NetBeans IDE 6.9 You can chose to listen to a section of talks using the agenda view and search for related content while watching a presentation. Enjoy the Java content and vote on it!

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Odd Profiler Results with EF4

- by AjarnMark

I have been doing some testing of using the Microsoft Entity Framework 4 with stored procedures and ran across some really odd results in SQL Server Profiler. The application that is running which uses Entity Framework 4 is a simple Web Application written in C#, and the Entity Data Model is actually contained in a referenced class library of its own. I’ll write more about my experiences with this later. For now the question is, why does SQL Profiler think that the stored procedure is running in Master, and not in my application database? While analyzing the effects of using custom helper methods on my EDM classes to call the stored procedure, I decided to run Profiler while I stepped through the code so that I had a clear understanding of exactly when and what calls were made to the SQL Server. I ran Profiler switching back and forth between the TSQL and TSQL_SP templates. However, to reduce the amount of results rows I needed to wade through, I set a filter on DatabaseID to be equal to my application’s database. Each time I ran this, the only thing that I saw was an Audit:Login to the database, but no procedure or T-SQL statements executed, yet I was definitely getting results back to my web page. I tried other Profiler templates, still filtering on DatabaseID (tangent: I found, at least back in SQL 2000 Profiler, that filtering on DatabaseID was more reliable than filtering on DatabaseName. Even though I’m now running SQL 2008, that habit sticks with me). Still no results other than the Login. Very weird! Finally, I decided to run Profiler with no filtering and discovered that that lines which represent my stored procedure and its T-SQL commands are all marked with DatabaseID = 1, which is Master. Why in the world would that be? My procedure is definitely in the application database, and not in Master, and there is nothing funny about the call to the procedure evident in Profiler (i.e. it is not called as MyAppDB.dbo.MyProcName, but rather just dbo.MyProcName). There must be something funny with the way the Entity Framework is wrapping this call, and I don’t like it…I don’t like it one bit. My primary PROD server contains 40+ databases on it, and when I need to profile something, I expect to be able to filter based on DatabaseID (for the record, I displayed DatabaseName in my results, too, and it also shows Master). I find the same pattern of everything except the Login showing up as being in Master when I run my version that uses standard LINQ to Entities instead of stored procedures, so that suggests it is not my code, but rather something funny with SQL Server 2008 Profiler or the Entity Framework. If you have any ideas about why this might be so, please comment below.

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Just another web startup - platform comparison

- by Holland

I'm looking to do a web startup which involves something along the lines of an ecommerce site, yet a little more in depth than that. While it's something that I would rather not go into detail with in terms of the initial idea, I can specify (on a basic level) what would be required of the website. If you have any observations or opinions derived from personal experience, which relate to what you see here, I'd appreciate it if you could share these. Paypal's API interaction (definitely). From what I've read about their API, integration with it into their website is VERY expensive, so I'd probably hold off on that until I've (hopefully) generated money and write my own simple credit-card interaction system. SQL Backend (obviously) PostgreSQL seems like a pretty good choice, as from what I've read, it's structure is a bit more "object-oriented" than, say, MySQL. Then again, I've used MySQL before and haven't had much problem with it whatsoever. Would it be worth learning PostgreSQL for this purpose? Java or .Net implementation (Preferably Mono, so I can use .Net while hosting the website using Apache). The reason for this is because, frankly, while I know PHP is a great platform to develop websites with, I hate developing with it. Before someone chimes in and flames me for saying that, note that I have nothing against the language, I just don't like it for my purposes. While Mono may be good to go with, I'm aware that ASP.Net MVC 3 hasn't been released for Mono yet, which may be a pain to work with, without their Razor syntax. Ontop of that, it seems Java is completely FULL of class libraries which deal with web development, that can be downloaded from the web. If anyone has any experience with these, I'd appreciate if that were posted. From what I've read about Spring and Struts2, they seem to be the best out there - especially since they're (AFAIK) MVC. I've considered Python and Django, which do seem REALLY nice, but I don't know much Python, and I'd rather start with something that I already know (language-wise; not framework-wise) than dive into learning a language AND a new framework. I'd REALLY like to be able to host my website via Apache, rather than using Windows Server or anything like that, as, frankly, I hate their setup. I'm not dissing it in any way, shape, or form, I'm just saying I dislike it. <3 terminal config. If there is a good reason to with Windows Server, however, I'd be willing to learn it. C# has a lot of things that Java appears not to have, including Delegates, unsigned types, and LINQ. Is there anything that Java has which can counter these?

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Silverlight Cream for March 13, 2011 -- #1059

- by Dave Campbell

In this Issue: András Velvárt, WIndowsPhoneGeek(-2-), Jesse Liberty(-2-), Victor Gaudioso, Kunal Chowdhury, Jeremy Likness, Michael Crump, and Dhananjay Kumar. Above the Fold: Silverlight: "Application Library Caching in Silverlight 4" Kunal Chowdhury WP7: "Handling WP7 orientation changes via Visual States" András Velvárt Shoutouts: Joe McBride gave a MEF Head User Group presentation and has posted How to Become a MEF Head – Slides & Code From SilverlightCream.com: Handling WP7 orientation changes via Visual States András Velvárt has an Expression Blend/WP7 post up discussing WP7 orientation changes and handling them via Visual States ... see an example from his SurfCube app, and a behavior to handle the control... with source. WP7 PerformanceProgressBar in depth WIndowsPhoneGeek has a post up discussing the WP7 Performance bar from the Windows Phone Toolkit. This is an update on the Toolkit based on the Feb 2011 release. Great explanation of the PerformanceProgressBar, external links, and sample code. Getting data out of WP7 WMAppManifest is easy with Coding4Fun PhoneHelper Next WindowsPhoneGeek has a post up about the PhoneHelper in the Coding4Fun TOolkit, and using it to get data out of the WMAppManifest easily. Good discussion, Links, and code as always Silverlight Unit Test For Phone In Jesse Liberty's "Windows Phone From Scratch" number 41, he's discussing Unit Testing for WP7... he gives some good external links and some good examples. Yet Another Podcast #27–Paul Betts Jesse Liberty's next post is his "Yet Another Podcast" number 27, and an interview with Paul Betts, the creator of Reactive UI... check out the podcast and also the good links listed. New Silverlight Video Tutorial: How to use the Fluid Move Behavior Victor Gaudioso has a new video tutorial up on using the Fluid Move Behavior... making a selected item animate from a ListBox to a Master Details Grid. Application Library Caching in Silverlight 4 Kunal Chowdhury takes a break from SilverlightZone long enough to write a post about Application Library Caching... for example on-demand loading of a 3rd-party XAP. Jounce Part 13: Navigation Parameters Jeremy Likness has his 13th post of a series in understanding his Jounce MVVM framework up. This episode surrounds a new release and what it contains, the primary focus being navigation parameters... that is you can raise a navigation event with a payload. Profiling Silverlight Applications after installing Visual Studio 2010 Service Pack 1 Michael Crump digs into the performance wizard for Silverlight that we get with VS2010 SP1. He shows how to get and read a profile... great intro to a new tool. Binding XML File to Data Grid in Silverlight Dhananjay Kumar demonstrates reading an XML file using LINQ to XML and binding the result to a Silverlight DataGrid Stay in the 'Light! Twitter SilverlightNews | Twitter WynApse | WynApse.com | Tagged Posts | SilverlightCream Join me @ SilverlightCream | Phoenix Silverlight User Group Technorati Tags: Silverlight Silverlight 3 Silverlight 4 Windows Phone MIX10

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Adding Attributes to Generated Classes

ASP.NET MVC 2 adds support for data annotations, implemented via attributes on your model classes. Depending on your design, you may be using an OR/M tool like Entity Framework or LINQ-to-SQL to generate your entity classes, and you may further be using these entities directly as your Model. This is fairly common, and alleviates the need to do mapping between POCO domain objects and such entities (though there are certainly pros and cons to using such entities directly). As an example, the current version of the NerdDinner application (available on CodePlex at nerddinner.codeplex.com) uses Entity Framework for its model. Thus, there is a NerdDinner.edmx file in the project, and a generated NerdDinner.Models.Dinner class. Fortunately, these generated classes are marked as partial, so you can extend their behavior via your own partial class in a separate file. However, if for instance the generated Dinner class has a property Title of type string, you cant then add your own Title of type string for the purpose of adding data annotations to it, like this: public partial class Dinner { [Required] public string Title { get;set; } } This will result in a compilation error, because the generated Dinner class already contains a definition of Title. How then can we add attributes to this generated code? Do we need to go into the T4 template and add a special case that says if were generated a Dinner class and it has a Title property, add this attribute? Ick. MetadataType to the Rescue The MetadataType attribute can be used to define a type which contains attributes (metadata) for a given class. It is applied to the class you want to add metadata to (Dinner), and it refers to a totally separate class to which youre free to add whatever methods and properties you like. Using this attribute, our partial Dinner class might look like this: [MetadataType(typeof(Dinner_Validation))] public partial class Dinner {} public class Dinner_Validation { [Required] public string Title { get; set; } } In this case the Dinner_Validation class is public, but if you were concerned about muddying your API with such classes, it could instead have been created as a private class within Dinner. Having the validation attributes specified in their own class (with no other responsibilities) complies with the Single Responsibility Principle and makes it easy for you to test that the validation rules you expect are in place via these annotations/attributes. Thanks to Julie Lerman for her help with this. Right after she showed me how to do this, I realized it was also already being done in the project I was working on. Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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Using the ASP.NET Cache to cache data in a Model or Business Object layer, without a dependency on System.Web in the layer - Part One.

- by Rhames

ASP.NET applications can make use of the System.Web.Caching.Cache object to cache data and prevent repeated expensive calls to a database or other store. However, ideally an application should make use of caching at the point where data is retrieved from the database, which typically is inside a Business Objects or Model layer. One of the key features of using a UI pattern such as Model-View-Presenter (MVP) or Model-View-Controller (MVC) is that the Model and Presenter (or Controller) layers are developed without any knowledge of the UI layer. Introducing a dependency on System.Web into the Model layer would break this independence of the Model from the View. This article gives a solution to this problem, using dependency injection to inject the caching implementation into the Model layer at runtime. This allows caching to be used within the Model layer, without any knowledge of the actual caching mechanism that will be used. Create a sample application to use the caching solution Create a test SQL Server database This solution uses a SQL Server database with the same Sales data used in my previous post on calculating running totals. The advantage of using this data is that it gives nice slow queries that will exaggerate the effect of using caching! To create the data, first create a new SQL database called CacheSample. Next run the following script to create the Sale table and populate it: USE CacheSample GO CREATE TABLE Sale(DayCount smallint, Sales money) CREATE CLUSTERED INDEX ndx_DayCount ON Sale(DayCount) go INSERT Sale VALUES (1,120) INSERT Sale VALUES (2,60) INSERT Sale VALUES (3,125) INSERT Sale VALUES (4,40) DECLARE @DayCount smallint, @Sales money SET @DayCount = 5 SET @Sales = 10 WHILE @DayCount < 5000 BEGIN INSERT Sale VALUES (@DayCount,@Sales) SET @DayCount = @DayCount + 1 SET @Sales = @Sales + 15 END Next create a stored procedure to calculate the running total, and return a specified number of rows from the Sale table, using the following script: USE [CacheSample] GO SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO -- ============================================= -- Author: Robin -- Create date: -- Description: -- ============================================= CREATE PROCEDURE [dbo].[spGetRunningTotals] -- Add the parameters for the stored procedure here @HighestDayCount smallint = null AS BEGIN -- SET NOCOUNT ON added to prevent extra result sets from -- interfering with SELECT statements. SET NOCOUNT ON; IF @HighestDayCount IS NULL SELECT @HighestDayCount = MAX(DayCount) FROM dbo.Sale DECLARE @SaleTbl TABLE (DayCount smallint, Sales money, RunningTotal money) DECLARE @DayCount smallint, @Sales money, @RunningTotal money SET @RunningTotal = 0 SET @DayCount = 0 DECLARE rt_cursor CURSOR FOR SELECT DayCount, Sales FROM Sale ORDER BY DayCount OPEN rt_cursor FETCH NEXT FROM rt_cursor INTO @DayCount,@Sales WHILE @@FETCH_STATUS = 0 AND @DayCount <= @HighestDayCount BEGIN SET @RunningTotal = @RunningTotal + @Sales INSERT @SaleTbl VALUES (@DayCount,@Sales,@RunningTotal) FETCH NEXT FROM rt_cursor INTO @DayCount,@Sales END CLOSE rt_cursor DEALLOCATE rt_cursor SELECT DayCount, Sales, RunningTotal FROM @SaleTbl END GO Create the Sample ASP.NET application In Visual Studio create a new solution and add a class library project called CacheSample.BusinessObjects and an ASP.NET web application called CacheSample.UI. The CacheSample.BusinessObjects project will contain a single class to represent a Sale data item, with all the code to retrieve the sales from the database included in it for simplicity (normally I would at least have a separate Repository or other object that is responsible for retrieving data, and probably a data access layer as well, but for this sample I want to keep it simple). The C# code for the Sale class is shown below: using System; using System.Collections.Generic; using System.Data; using System.Data.SqlClient; namespace CacheSample.BusinessObjects { public class Sale { public Int16 DayCount { get; set; } public decimal Sales { get; set; } public decimal RunningTotal { get; set; } public static IEnumerable<Sale> GetSales(int? highestDayCount) { List<Sale> sales = new List<Sale>(); SqlParameter highestDayCountParameter = new SqlParameter("@HighestDayCount", SqlDbType.SmallInt); if (highestDayCount.HasValue) highestDayCountParameter.Value = highestDayCount; else highestDayCountParameter.Value = DBNull.Value; string connectionStr = System.Configuration.ConfigurationManager .ConnectionStrings["CacheSample"].ConnectionString; using(SqlConnection sqlConn = new SqlConnection(connectionStr)) using (SqlCommand sqlCmd = sqlConn.CreateCommand()) { sqlCmd.CommandText = "spGetRunningTotals"; sqlCmd.CommandType = CommandType.StoredProcedure; sqlCmd.Parameters.Add(highestDayCountParameter); sqlConn.Open(); using (SqlDataReader dr = sqlCmd.ExecuteReader()) { while (dr.Read()) { Sale newSale = new Sale(); newSale.DayCount = dr.GetInt16(0); newSale.Sales = dr.GetDecimal(1); newSale.RunningTotal = dr.GetDecimal(2); sales.Add(newSale); } } } return sales; } } } The static GetSale() method makes a call to the spGetRunningTotals stored procedure and then reads each row from the returned SqlDataReader into an instance of the Sale class, it then returns a List of the Sale objects, as IEnnumerable<Sale>. A reference to System.Configuration needs to be added to the CacheSample.BusinessObjects project so that the connection string can be read from the web.config file. In the CacheSample.UI ASP.NET project, create a single web page called ShowSales.aspx, and make this the default start up page. This page will contain a single button to call the GetSales() method and a label to display the results. The html mark up and the C# code behind are shown below: ShowSales.aspx <%@ Page Language="C#" AutoEventWireup="true" CodeBehind="ShowSales.aspx.cs" Inherits="CacheSample.UI.ShowSales" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head runat="server"> <title>Cache Sample - Show All Sales</title> </head> <body> <form id="form1" runat="server"> <div> <asp:Button ID="btnTest1" runat="server" onclick="btnTest1_Click" Text="Get All Sales" />     <asp:Label ID="lblResults" runat="server"></asp:Label> </div> </form> </body> </html> ShowSales.aspx.cs using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.UI; using System.Web.UI.WebControls; using CacheSample.BusinessObjects; namespace CacheSample.UI { public partial class ShowSales : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { } protected void btnTest1_Click(object sender, EventArgs e) { System.Diagnostics.Stopwatch stopWatch = new System.Diagnostics.Stopwatch(); stopWatch.Start(); var sales = Sale.GetSales(null); var lastSales = sales.Last(); stopWatch.Stop(); lblResults.Text = string.Format( "Count of Sales: {0}, Last DayCount: {1}, Total Sales: {2}. Query took {3} ms", sales.Count(), lastSales.DayCount, lastSales.RunningTotal, stopWatch.ElapsedMilliseconds); } } } Finally we need to add a connection string to the CacheSample SQL Server database, called CacheSample, to the web.config file: <?xmlversion="1.0"?> <configuration> <connectionStrings> <addname="CacheSample" connectionString="data source=.\SQLEXPRESS;Integrated Security=SSPI;Initial Catalog=CacheSample" providerName="System.Data.SqlClient" /> </connectionStrings> <system.web> <compilationdebug="true"targetFramework="4.0" /> </system.web> </configuration> Run the application and click the button a few times to see how long each call to the database takes. On my system, each query takes about 450ms. Next I shall look at a solution to use the ASP.NET caching to cache the data returned by the query, so that subsequent requests to the GetSales() method are much faster. Adding Data Caching Support I am going to create my caching support in a separate project called CacheSample.Caching, so the next step is to add a class library to the solution. We shall be using the application configuration to define the implementation of our caching system, so we need a reference to System.Configuration adding to the project. ICacheProvider<T> Interface The first step in adding caching to our application is to define an interface, called ICacheProvider, in the CacheSample.Caching project, with methods to retrieve any data from the cache or to retrieve the data from the data source if it is not present in the cache. Dependency Injection will then be used to inject an implementation of this interface at runtime, allowing the users of the interface (i.e. the CacheSample.BusinessObjects project) to be completely unaware of how the caching is actually implemented. As data of any type maybe retrieved from the data source, it makes sense to use generics in the interface, with a generic type parameter defining the data type associated with a particular instance of the cache interface implementation. The C# code for the ICacheProvider interface is shown below: using System; using System.Collections.Generic; namespace CacheSample.Caching { public interface ICacheProvider { } public interface ICacheProvider<T> : ICacheProvider { T Fetch(string key, Func<T> retrieveData, DateTime? absoluteExpiry, TimeSpan? relativeExpiry); IEnumerable<T> Fetch(string key, Func<IEnumerable<T>> retrieveData, DateTime? absoluteExpiry, TimeSpan? relativeExpiry); } } The empty non-generic interface will be used as a type in a Dictionary generic collection later to store instances of the ICacheProvider<T> implementation for reuse, I prefer to use a base interface when doing this, as I think the alternative of using object makes for less clear code. The ICacheProvider<T> interface defines two overloaded Fetch methods, the difference between these is that one will return a single instance of the type T and the other will return an IEnumerable<T>, providing support for easy caching of collections of data items. Both methods will take a key parameter, which will uniquely identify the cached data, a delegate of type Func<T> or Func<IEnumerable<T>> which will provide the code to retrieve the data from the store if it is not present in the cache, and absolute or relative expiry policies to define when a cached item should expire. Note that at present there is no support for cache dependencies, but I shall be showing a method of adding this in part two of this article. CacheProviderFactory Class We need a mechanism of creating instances of our ICacheProvider<T> interface, using Dependency Injection to get the implementation of the interface. To do this we shall create a CacheProviderFactory static class in the CacheSample.Caching project. This factory will provide a generic static method called GetCacheProvider<T>(), which shall return instances of ICacheProvider<T>. We can then call this factory method with the relevant data type (for example the Sale class in the CacheSample.BusinessObject project) to get a instance of ICacheProvider for that type (e.g. call CacheProviderFactory.GetCacheProvider<Sale>() to get the ICacheProvider<Sale> implementation). The C# code for the CacheProviderFactory is shown below: using System; using System.Collections.Generic; using CacheSample.Caching.Configuration; namespace CacheSample.Caching { public static class CacheProviderFactory { private static Dictionary<Type, ICacheProvider> cacheProviders = new Dictionary<Type, ICacheProvider>(); private static object syncRoot = new object(); ///<summary> /// Factory method to create or retrieve an implementation of the /// ICacheProvider interface for type <typeparamref name="T"/>. ///</summary> ///<typeparam name="T"> /// The type that this cache provider instance will work with ///</typeparam> ///<returns>An instance of the implementation of ICacheProvider for type ///<typeparamref name="T"/>, as specified by the application /// configuration</returns> public static ICacheProvider<T> GetCacheProvider<T>() { ICacheProvider<T> cacheProvider = null; // Get the Type reference for the type parameter T Type typeOfT = typeof(T); // Lock the access to the cacheProviders dictionary // so multiple threads can work with it lock (syncRoot) { // First check if an instance of the ICacheProvider implementation // already exists in the cacheProviders dictionary for the type T if (cacheProviders.ContainsKey(typeOfT)) cacheProvider = (ICacheProvider<T>)cacheProviders[typeOfT]; else { // There is not already an instance of the ICacheProvider in // cacheProviders for the type T // so we need to create one // Get the Type reference for the application's implementation of // ICacheProvider from the configuration Type cacheProviderType = Type.GetType(CacheProviderConfigurationSection.Current. CacheProviderType); if (cacheProviderType != null) { // Now get a Type reference for the Cache Provider with the // type T generic parameter Type typeOfCacheProviderTypeForT = cacheProviderType.MakeGenericType(new Type[] { typeOfT }); if (typeOfCacheProviderTypeForT != null) { // Create the instance of the Cache Provider and add it to // the cacheProviders dictionary for future use cacheProvider = (ICacheProvider<T>)Activator. CreateInstance(typeOfCacheProviderTypeForT); cacheProviders.Add(typeOfT, cacheProvider); } } } } return cacheProvider; } } } As this code uses Activator.CreateInstance() to create instances of the ICacheProvider<T> implementation, which is a slow process, the factory class maintains a Dictionary of the previously created instances so that a cache provider needs to be created only once for each type. The type of the implementation of ICacheProvider<T> is read from a custom configuration section in the application configuration file, via the CacheProviderConfigurationSection class, which is described below. CacheProviderConfigurationSection Class The implementation of ICacheProvider<T> will be specified in a custom configuration section in the application’s configuration. To handle this create a folder in the CacheSample.Caching project called Configuration, and add a class called CacheProviderConfigurationSection to this folder. This class will extend the System.Configuration.ConfigurationSection class, and will contain a single string property called CacheProviderType. The C# code for this class is shown below: using System; using System.Configuration; namespace CacheSample.Caching.Configuration { internal class CacheProviderConfigurationSection : ConfigurationSection { public static CacheProviderConfigurationSection Current { get { return (CacheProviderConfigurationSection) ConfigurationManager.GetSection("cacheProvider"); } } [ConfigurationProperty("type", IsRequired=true)] public string CacheProviderType { get { return (string)this["type"]; } } } } Adding Data Caching to the Sales Class We now have enough code in place to add caching to the GetSales() method in the CacheSample.BusinessObjects.Sale class, even though we do not yet have an implementation of the ICacheProvider<T> interface. We need to add a reference to the CacheSample.Caching project to CacheSample.BusinessObjects so that we can use the ICacheProvider<T> interface within the GetSales() method. Once the reference is added, we can first create a unique string key based on the method name and the parameter value, so that the same cache key is used for repeated calls to the method with the same parameter values. Then we get an instance of the cache provider for the Sales type, using the CacheProviderFactory, and pass the existing code to retrieve the data from the database as the retrievalMethod delegate in a call to the Cache Provider Fetch() method. The C# code for the modified GetSales() method is shown below: public static IEnumerable<Sale> GetSales(int? highestDayCount) { string cacheKey = string.Format("CacheSample.BusinessObjects.GetSalesWithCache({0})", highestDayCount); return CacheSample.Caching.CacheProviderFactory. GetCacheProvider<Sale>().Fetch(cacheKey, delegate() { List<Sale> sales = new List<Sale>(); SqlParameter highestDayCountParameter = new SqlParameter("@HighestDayCount", SqlDbType.SmallInt); if (highestDayCount.HasValue) highestDayCountParameter.Value = highestDayCount; else highestDayCountParameter.Value = DBNull.Value; string connectionStr = System.Configuration.ConfigurationManager. ConnectionStrings["CacheSample"].ConnectionString; using (SqlConnection sqlConn = new SqlConnection(connectionStr)) using (SqlCommand sqlCmd = sqlConn.CreateCommand()) { sqlCmd.CommandText = "spGetRunningTotals"; sqlCmd.CommandType = CommandType.StoredProcedure; sqlCmd.Parameters.Add(highestDayCountParameter); sqlConn.Open(); using (SqlDataReader dr = sqlCmd.ExecuteReader()) { while (dr.Read()) { Sale newSale = new Sale(); newSale.DayCount = dr.GetInt16(0); newSale.Sales = dr.GetDecimal(1); newSale.RunningTotal = dr.GetDecimal(2); sales.Add(newSale); } } } return sales; }, null, new TimeSpan(0, 10, 0)); } This example passes the code to retrieve the Sales data from the database to the Cache Provider as an anonymous method, however it could also be written as a lambda. The main advantage of using an anonymous function (method or lambda) is that the code inside the anonymous function can access the parameters passed to the GetSales() method. Finally the absolute expiry is set to null, and the relative expiry set to 10 minutes, to indicate that the cache entry should be removed 10 minutes after the last request for the data. As the ICacheProvider<T> has a Fetch() method that returns IEnumerable<T>, we can simply return the results of the Fetch() method to the caller of the GetSales() method. This should be all that is needed for the GetSales() method to now retrieve data from a cache after the first time the data has be retrieved from the database. Implementing a ASP.NET Cache Provider The final step is to actually implement the ICacheProvider<T> interface, and add the implementation details to the web.config file for the dependency injection. The cache provider implementation needs to have access to System.Web. Therefore it could be placed in the CacheSample.UI project, or in its own project that has a reference to System.Web. Implementing the Cache Provider in a separate project is my favoured approach. Create a new project inside the solution called CacheSample.CacheProvider, and add references to System.Web and CacheSample.Caching to this project. Add a class to the project called AspNetCacheProvider. Make the class a generic class by adding the generic parameter <T> and indicate that the class implements ICacheProvider<T>. The C# code for the AspNetCacheProvider class is shown below: using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.Caching; using CacheSample.Caching; namespace CacheSample.CacheProvider { public class AspNetCacheProvider<T> : ICacheProvider<T> { #region ICacheProvider<T> Members public T Fetch(string key, Func<T> retrieveData, DateTime? absoluteExpiry, TimeSpan? relativeExpiry) { return FetchAndCache<T>(key, retrieveData, absoluteExpiry, relativeExpiry); } public IEnumerable<T> Fetch(string key, Func<IEnumerable<T>> retrieveData, DateTime? absoluteExpiry, TimeSpan? relativeExpiry) { return FetchAndCache<IEnumerable<T>>(key, retrieveData, absoluteExpiry, relativeExpiry); } #endregion #region Helper Methods private U FetchAndCache<U>(string key, Func<U> retrieveData, DateTime? absoluteExpiry, TimeSpan? relativeExpiry) { U value; if (!TryGetValue<U>(key, out value)) { value = retrieveData(); if (!absoluteExpiry.HasValue) absoluteExpiry = Cache.NoAbsoluteExpiration; if (!relativeExpiry.HasValue) relativeExpiry = Cache.NoSlidingExpiration; HttpContext.Current.Cache.Insert(key, value, null, absoluteExpiry.Value, relativeExpiry.Value); } return value; } private bool TryGetValue<U>(string key, out U value) { object cachedValue = HttpContext.Current.Cache.Get(key); if (cachedValue == null) { value = default(U); return false; } else { try { value = (U)cachedValue; return true; } catch { value = default(U); return false; } } } #endregion } } The two interface Fetch() methods call a private method called FetchAndCache(). This method first checks for a element in the HttpContext.Current.Cache with the specified cache key, and if so tries to cast this to the specified type (either T or IEnumerable<T>). If the cached element is found, the FetchAndCache() method simply returns it. If it is not found in the cache, the method calls the retrievalMethod delegate to get the data from the data source, and then adds this to the HttpContext.Current.Cache. The final step is to add the AspNetCacheProvider class to the relevant custom configuration section in the CacheSample.UI.Web.Config file. To do this there needs to be a <configSections> element added as the first element in <configuration>. This will match a custom section called <cacheProvider> with the CacheProviderConfigurationSection. Then we add a <cacheProvider> element, with a type property set to the fully qualified assembly name of the AspNetCacheProvider class, as shown below: <?xmlversion="1.0"?> <configuration> <configSections> <sectionname="cacheProvider" type="CacheSample.Base.Configuration.CacheProviderConfigurationSection, CacheSample.Base" /> </configSections> <connectionStrings> <addname="CacheSample" connectionString="data source=.\SQLEXPRESS;Integrated Security=SSPI;Initial Catalog=CacheSample" providerName="System.Data.SqlClient" /> </connectionStrings> <cacheProvidertype="CacheSample.CacheProvider.AspNetCacheProvider`1, CacheSample.CacheProvider, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null"> </cacheProvider> <system.web> <compilationdebug="true"targetFramework="4.0" /> </system.web> </configuration> One point to note is that the fully qualified assembly name of the AspNetCacheProvider class includes the notation `1 after the class name, which indicates that it is a generic class with a single generic type parameter. The CacheSample.UI project needs to have references added to CacheSample.Caching and CacheSample.CacheProvider so that the actual application is aware of the relevant cache provider implementation. Conclusion After implementing this solution, you should have a working cache provider mechanism, that will allow the middle and data access layers to implement caching support when retrieving data, without any knowledge of the actually caching implementation. If the UI is not ASP.NET based, if for example it is Winforms or WPF, the implementation of ICacheProvider<T> would be written around whatever technology is available. It could even be a standalone caching system that takes full responsibility for adding and removing items from a global store. The next part of this article will show how this caching mechanism may be extended to provide support for cache dependencies, such as the System.Web.Caching.SqlCacheDependency. Another possible extension would be to cache the cache provider implementations instead of storing them in a static Dictionary in the CacheProviderFactory. This would prevent a build up of seldom used cache providers in the application memory, as they could be removed from the cache if not used often enough, although in reality there are probably unlikely to be vast numbers of cache provider implementation instances, as most applications do not have a massive number of business object or model types.

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ASP.NET Hosting :: ASP.NET File Upload Control

- by mbridge

The asp.net FileUpload control allows a user to browse and upload files to the web server. From developers perspective, it is as simple as dragging and dropping the FileUpload control to the aspx page. An extra control, like a Button control, or some other control is needed, to actually save the file. <asp:FileUploadID="FileUpload1"runat="server"/> <asp:ButtonID="B1"runat="server"Text="Save"OnClick="B1_Click"/> By default, the FileUpload control allows a maximum of 4MB file to be uploaded and the execution timeout is 110 seconds. These properties can be changed from within the web.config file’s httpRuntime section. The maxRequestLength property determines the maximum file size that can be uploaded. The executionTimeout property determines the maximum time for execution. <httpRuntimemaxRequestLength="8192"executionTimeout="220"/> From code behind, the mime type, size of the file, file name and the extension of the file can be obtained. The maximum file size that can be uploaded can be obtained and modified using the System.Web.Configuration.HttpRuntimeSection class. Files can be alternatively saved using the System.IO.HttpFileCollection class. This collection class can be populated using the Request.Files property. The collection contains HttpPostedFile class which contains a reference to the class. using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.UI; using System.Web.UI.WebControls; using System.IO; using System.Configuration; using System.Web.Configuration; namespace WebApplication1 { public partial class WebControls : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { } //Using FileUpload control to upload and save files protected void B1_Click(object sender, EventArgs e) { if (FileUpload1.HasFile && FileUpload1.PostedFile.ContentLength > 0) { //mime type of the uploaded file string mimeType = FileUpload1.PostedFile.ContentType; //size of the uploaded file int size = FileUpload1.PostedFile.ContentLength; // bytes //extension of the uploaded file string extension = System.IO.Path.GetExtension(FileUpload1.FileName); //save file string path = Server.MapPath("path"); FileUpload1.SaveAs(path + FileUpload1.FileName); } //maximum file size allowed HttpRuntimeSection rt = new HttpRuntimeSection(); rt.MaxRequestLength = rt.MaxRequestLength * 2; int length = rt.MaxRequestLength; //execution timeout TimeSpan ts = rt.ExecutionTimeout; double secomds = ts.TotalSeconds; } //Using Request.Files to save files private void AltSaveFile() { HttpFileCollection coll = Request.Files; for (int i = 0; i < coll.Count; i++) { HttpPostedFile file = coll[i]; if (file.ContentLength > 0) ;//do something } } } }

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Retreiving upcoming calendar events from a Google Calendar

- by brian_ritchie

Google has a great cloud-based calendar service that is part of their Gmail product. Besides using it as a personal calendar, you can use it to store events for display on your web site. The calendar is accessible through Google's GData API for which they provide a C# SDK. Here's some code to retrieve the upcoming entries from the calendar: .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: Consolas, "Courier New", Courier, Monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } 1: public class CalendarEvent 2: { 3: public string Title { get; set; } 4: public DateTime StartTime { get; set; } 5: } 6: 7: public class CalendarHelper 8: { 9: public static CalendarEvent[] GetUpcomingCalendarEvents 10: (int numberofEvents) 11: { 12: CalendarService service = new CalendarService("youraccount"); 13: EventQuery query = new EventQuery(); 14: query.Uri = new Uri( 15: "http://www.google.com/calendar/feeds/userid/public/full"); 16: query.FutureEvents = true; 17: query.SingleEvents = true; 18: query.SortOrder = CalendarSortOrder.ascending; 19: query.NumberToRetrieve = numberofEvents; 20: query.ExtraParameters = "orderby=starttime"; 21: var events = service.Query(query); 22: return (from e in events.Entries select new CalendarEvent() 23: { StartTime=(e as EventEntry).Times[0].StartTime, 24: Title = e.Title.Text }).ToArray(); 25: } 26: } There are a few special "tricks" to make this work: "SingleEvents" flag will flatten out reoccurring events "FutureEvents", "SortOrder", and the "orderby" parameters will get the upcoming events. "NumberToRetrieve" will limit the amount coming back I then using Linq to Objects to put the results into my own DTO for use by my model. It is always a good idea to place data into your own DTO for use within your MVC model. This protects the rest of your code from changes to the underlying calendar source or API.

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Stagnating in programming

- by Coder

Time after time this question came up in my mind, but up until today I wasn't thinking about it much. I have been programming for maybe around 8 years now, and for the last two years it seems I'm not as keen to pick up new technologies anymore. Maybe that's a burnout or something, but I'd say it's experience and what I like, that's stopping me from running after the latest and greatest. I'm C++ developer, by this I mean, I love close to metal programming. I have no problems tracing problems through assembly, using tools like WinDbg or HexView. When I use constructs, I think about how they are realized underneath, how the bits are set and unset under the hood. I love battling with complex threading problems and doing everything hardcore way, even by hand if the regular solutions seem half baked. But I also love the C++0x stuff, and use it a lot. And all C++ code as long as it's not cumbersome compared to C counterparts, sometimes I also fall back to sort of "Super C" if the C++ way is ugly. And then there are all other developers who seem to be way more forward looking, .Net 4.0 MVC, WPF, all those Microsoft X#s, LINQ languages, XML and XSLT, mobile devices and so on. I have done a considerable amount of .NET, SQL, ASPX programming, but the further I go, the less I want to try those technologies. Is that bad? Almost every day I hear people saying that managed code is the only way forward, WPF is the way to go. I hear that C++ is godawful, and you can't code anything in it that's somewhat stable. But I don't buy it. With the experience I have, and the knowledge of how native code is compiled and executes, I can say I find it extremely rare that C++ code is unstable, or leaks, or causes crashes that takes more than 30 seconds to identify and fix. And to tell the truth, I've seen enough problems with other "cool" languages that I'd say C++ is even more stable and production proof than the safe languages, at least for me. The only thing that scares me in C++ is new frameworks, I don't trust them, and I use them extra sparingly. STL - yes, ATL - very sparingly, everything else... Well, not very keen on it. Most huge problems I've ran into, all were related to frameworks, not the language itself. Some overrided operator here, bad hierarchy there, poor class design here, mystical castings there. Other than that, C/C++ (yes, I use them together) still seems a very controlled and stable way to develop applications. Am I stagnating? Should I switch a profession, or force myself in all that marketing hype? Are there more developers who feel the same way?

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Hello From South Florida

- by Sam Abraham

Fellow Blog Readers: I figured I use my first blog post on GeeksWithBlogs to introduce myself. I recently relocated from Long Island, NY to South Florida where I joined a local company as Software Engineer specializing in technologies such as C#, ASP.Net 3.5, WCF, Silverlight, SQL Server 2008 and LINQ, to name a few. I am an MCP and MCTS ASP.Net 3.5, looking to get my .Net 4.0 certification soon. Having been in industry for a few years so far, I figured I would share with you my take on the importance of being involved(at least attending) in local user groups. I am a firm believer that besides using a certain technology, the best way to expand one’s knowledge is by sharing it with others and being equally open to learn from others just as much as you are willing to share what you know. In my opinion, an important factor that makes a good developer stand-out is his/her ability to keep abreast with the latest and greatest even in areas outside his/her direct expertise. Additionally, having spoken to various recruiters, technical user group attendees are always favorably looked upon as genuinely interested in their field and willing to take the initiative to expand their knowledge which offers job candidates good leverage when competing for jobs. I believe I am very blessed to be in an area with a very strong and vibrant developer community. I found in the local .Net community leadership a genuine interest in constantly extending the opportunity to all developers to get more involved and encouraging those who are willing to take that initiative achieve their goal: Speak in meetings, volunteer at events or write and publish articles/blogs about latest and greatest technologies. With Vishal Shukla (Site director for the West Palm Beach .Net User Group) traveling overseas, I have been extended the opportunity to come on board as site coordinator for FladotNet's WPB .Net User Group along with Venkata Subramanian, an opportunity which I gratefully accepted. Being involved in running a .Net User Group will surely help me personally and professionally, but my real hope is to use this opportunity to assist in delivering the ultimate common-goal: spread the word about new .Net Technologies, help everybody get more involved and simply have fun learning new things. With my introduction out of the way, in the next few days I will be posting some notes on an upcoming talk I will be giving about MVC2 and VS2010 in mid-April. Environment.Exit(0); --Sam

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302: this blog will be closed

- by preishuber

After nearly 7 years I will discontinue blogging on this site. My resources are limited. You can reach my German blog which is used to support my customers. Looking back to a long an interesting journey ASP.NET by ScottGu That was the reason to attend this site and support Microsoft as much as I can. For that I was honored as ASP.NET MVP- thanks again. Meet Scoot several times. Great guy! Forums I have left NNTP forums a few years ago and now Microsoft closed it- It was my idea ;-) AJAX Was the wrong way- JQuery won the game IIS7 That is really a great plattform and the IIS team rules. I am sad that is so silent around that topic. ASP.NET after 2.0 Is no longer my world. I love ASP.NET and ASP.NET Server controls. I hate the discussion about how to follow the holy rules of MVC. Microsoft have dropped the goal to bring ASP.NET to #1 and accepted PHP is it. Facebook & Twittering Microblogging takes over a part of the blogging business. Shorter faster cheaper- or as SteveB mentioned - do more with less. Google Google is taking over the web. I am using Bing every time as I can but Google have more options. Sorry Microsoft you will loose that game. Apple That is not the biggest problem of Microsoft. the Ixxx takes over a small part but big money of the market, but the customers are not strongly linked. New wave new hype- Game over Apple. Silverlight My new home. I can reuse a lot of my skills and love the possibilitys. Silverligth will passing WPF-and strike Flash Windows phone 7 Also my skills fit. I just will use it for fun. I am not really satisfied about what I have heard from MIX. Guys from Redmond, I am sad to say you have been the best Smartphone OS and lost everything. The ADO vNext Story That will be the next mystic point. WCF, REST, JSON, ATOM and now OData. Nothing about SQL commands. LINQ, ORM is also not the final solution for multilayered disconnected async scenarios. Personally I prefere the OData idea and dislike the Swiss Army Knife (German Eierlegende Wollmilchsau) WCF. I am still in INETA Speakers board and I am glad to come to your user group. In all other cases you can hire me over ppedv AG. Good by and have good live.

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